What Type Of Algae Is This?

[jnms]

Can anyone tell what sort of algae this is?

I have checked Mr.Algae's site and I am not at all sure. Although the colour is Blue-Green it isn't slimy or anything like that. It grows almost 'crystal' like upon the sand substrate. It returns within 24 to 48hrs after I remove it.

These are the solutions I have tried so far.

1) Increased the water flow.
2) Replaced this portion of the substrate.
3) Added CO2
4) Stopped adding ferts
5) Cut back on feeding

Water perameters:
Ph: 7.1
Am: 0.0
Ni: 0.0
Na: 25
Kh: 15

I perform 25% to 35% water changes per week.

I use Tropica+ root tabs, there are about 8 in the tank which have been there for 6weeks now, the algae started about 3 weeks ago. I also started adding some Tropica Liquid ferts, though I haven't put much of that in at all, and have since added activated carbon to temporarily remove the 'trace elements'. The carbon will be coming back out again soon.

Finally, probably the most important observation; the algae almost entirely disappears overnight when the lights are off. It returns again about 2hrs after the lights have been turned on. I have two 30W lights, one came with the tank and is a standard 'white' lamp. The other is a Hagen Aqua-Glow. I have the lights on for two sets of 4 hours during the daytime with a two hour gap in between.

EDIT: Some more info. I actually have some brown algae in the tank (diatoms). The tank stats appear to be fine - though I have no test for phosphates (can phosphates cause brown algae?) This leads me to think it is a lighting issue. I that sometimes low light can cause brown algae.

Additionally my plants aren't growing very fast. They seemed to have really slowed down since I added the Aqua-Glo light. So right now I am considering adding more light. Thing is - do I replace my oldest light-bulb (the one that came with the tank) or do I add an additional third light bulb?

EDIT 2: It seems that the algae in the photos is indeed blue-green algae.

 

[Syphoniera]

To be crystal-like, could it be absorbing silicates from the sand?
Or perhaps be cyanobacteria just growing in a very fine layer over sand granules?
I've had it do that on gravel, so that it appears like discoloured gravel; could it be actually sand thinly coated with blue-green algae and therefore appearing to be crystalized?

Edit - cut a sentence and failed to realize that the algae was no longer specified.

 

[jnms]

Yes, I hadn't considered that. It does indeed look like each crystal of sand is thinly coated! Any idea what I can do about this?

 

[jnms]

Anyone able to help on what I can do about this?

Cheers...

 

[jnms]

Just another observation. The algae almost entirly disappears over night when the lights are off. It returns within about 2hrs of the lights being back on. Will add this info into my first post...

 

[Syphoniera]

I've had trouble with cyanobacteria in tanks where plants were melting, and had it clear when the plants were replaced with ones doing better.
Have you considered planting more heavily, to absorb the nutrients that the algae's growing from?
Blue green algae was one of the earliest life-forms and is ubiquitous because almost infinitely adaptable.
As fish continuously respire ammonia, what with Nature abhorring a vacuum and all, something will likely appear to use this nourishment - and if plants aren't outcompeting algae/cyanobacteria, that's what we tend to wind up with, to some degree or other.
And as bluegreen algae is toxic, it's of no use as a food source to fish or most invertebrates and so has a competetive edge in any take-over bids.
We might as well use Nature's way of establishing the sort of balance we want in our tanks, because algae, like rust, never sleeps.

 

[aaronnorth]

to absorb the nutrients that the algae's growing from?

It is cynobacteria, it doesnt need nutrients.

Causes:
ammonia
dirty filter
lots of organic matter
low nitrates

removal:
1) syphon out as much as possible
2) do a 50% w/c
3) cover tank up for 3 days, no lights, no CO2, no feeding/ peeking etc.
4) uncover tank and do another 50% w/c

The reason it goes away at night is because it needs light to grow, and basically what is happening is it is creating a blackout for a short period of time, but we need to extend this time to 3-5 days for it to be succesful.

 

[Syphoniera]

The august aaronnorth provides, as always, excellent advice.
But while it's very true that:

'It is cynobacteria, it doesnt need nutrients.

Causes:
ammonia
dirty filter
lots of organic matter
low nitrates ...'

3 of the 4 causal factors given involve high levels of nutrients which can cause cyano to prosper, even though it can survive without these.
Therefore, while being absolutely right in both respects, this statement may appear somewhat confusing as seeming contradictory, although it isn't, really.
And some very different approaches have worked, or not, as the case may be, because cyanobacteria has survived millennia through its ability to alter its requirements according to circumstance.

I've developed problems with this due to plant melt, and clearing that out and replacing the problem plants with new tends to clear the problem.
Then again, I have an old second-hand 10 gallon with the silicon seal having loose edges and trapped cyano behind.
The blue-green algae is inaccessible in there, creeps out at low levels across the glass, wiping it off causes bits to float loose in almost invisible shreds which are caught inside the filter, which both stores and recirculates it.
The tank had a low bioload of one male betta, one small Endler cross guppy and a (now deceased) ramshorn snail, with (normally) 25 - 30% weekly water changes, plants, low light - low nitrates...
I've had continual problems with it in that tank, and eventually took out most of the existing plants, replacing this with a Wisteria 'forest' which prevented the cyano from creeping across the gravel and low plants (stunted as a result) with little, tiny, uncleanable leaves.
The Wisteria not only sucked up nutrients (I usually add a dash of Flourish after waterchanges) but shielded the gravel from light over a large area.
Whether rightly or wrongly, it appears to me that this helped considerably.
But until I can transfer the fish elsewhere and close down that tank, I'll be struggling with that problem.


While I know nothing myself, it seems certain types of cyanobacteria can also survive without light, even if they appear to disappear.
It's incredibly adaptable and very interesting stuff, (when not in our aquaria) with a number of different, if often similar-appearing, types.
While a lot of the info below may not at first seem to apply, it will give a general idea of the complexity of something which ranges from a nuisance to a disaster when any of its myriad forms, some differentiated only by use of a microscope, appear in our tank.

Understand thine enemy...


http/lakes.chebucto.org/cyano.html

... The process of nitrogen fixation and the occurrence of gas vesicles are especially important to the success of nuisance species of blue-greens. The blue-greens are widely distributed over land and water, often in environments where no other vegetation can exist. Their fossils have been identified as over three billion years old. They were probably the chief primary producers of organic matter and the first organisms to release elemental oxygen, O2, into the primitive atmosphere, which was until then free from O2. Thus blue-greens were most probably responsible for a major evolutionary transformation leading to the development of aerobic metabolism and to the subsequent rise of higher plant and animal forms. They are referred to in literature by various names, chief among which are Cyanophyta, Myxophyta, Cyanochloronta, Cyanobacteria, blue-green algae, blue-green bacteria.
The majority of blue-greens are aerobic photoautotrophs: their life processes require only oxygen, light and inorganic substances. A species of Oscillatoria that is found in mud at the bottom of the Thames, are able to live anaerobically. They can live in extremes of temperatures -60°C to 85°C, and a few species are halophilic or salt tolerant (as high as 27%, for comparison, conc. of salt in seawater is 3%). Blue-greens can grow in full sunlight and in almost complete darkness. hey are often the first plants to colonize bare areas of rock and soil, as an example subsequent to cataclysmic volcanic explosion (at Krakatoa, Indonesia in 1883). Unlike more advanced organisms, these need no substances that have been preformed by other organisms.

At the onset of nitrogen limitation during bloom conditions, certain cells in Anabaena and Aphanizomenon evolve into heterocysts, which convert nitrogen gas into ammonium, which is then distributed to the neighboring cells of a filament. In addition, blue-greens that form symbiotic (mutually beneficial) relationships with a wide range of other life forms, can convert nitrogen gas into ammonium.

Finally, at the onset of adverse environmental conditions, some blue-greens can develop a modified cell, called an akinete. Akinetes contain large reserves of carbohydrates, and owing to their density and lack of gas vesicles, eventually settle to the lake bottom. They can tolerate adverse conditions such as the complete drying of a pond or the cold winter temperatures, and, as a consequence, akinetes serve as "seeds" for the growth of juvenile filaments when favorable conditions return. Heterocysts and akinetes are unique to the blue-greens. ...

http/lakes.chebucto.org/cyano.html#Measures

Measures to control the growth of blue-greens
Chemicals are widely used to prevent the growth of nuisance algae, and the commonest one being copper sulphate. A number of other algicides are phenolic compounds, amide derivatives, quaternary ammonium compounds and quinone derivatives. Dichloron aphthoquinone is selectively toxic to blue-greens. The hazards of using toxic chemicals indiscriminately in the natural environment are well documented.
Biological control is in principle possible, though not always practical and as effective. Invertebrates like cladocerans, copepods, ostracods and snails are known to graze on green algae and diatoms. Daphnia pulex has been reported to feed on Aphanizomenon flos-aquae while present in the form of single filaments or small colonies but avoid large raft-like colonies. The copepod Diaptomus has been implicated in the grazing of Anabaena populations in Severson Lake, Minnesota.

Micro-organisms (fungi, bacteria and viruses) appear to play an important part in regulating growth of blue-greens in freshwaters. Certain chytrids (fungal pathogens) specifically infest akinetes, other heterocysts. Bacterial pathogens belonging to the group of Myxobacteriales can effect rapid lysis of a wide range of unicellular and filamentous blue-greens, though heterocysts and akinetes remain generally unaffected. Viral pathogens belonging to the group of cyanophages exhibit some degree of host specifity. Phage AR-1 attacks Anabaenopsis, phages SM-1 and AS-1 are effective against the unicellular forms, Synechococcus and Microcystis, Phage C-1 lyses Cylindropermum, and the LPP-1 virus is effective against strains of Lyngbya, Phormidium and Plectonema.

The long-term approach is no doubt the systematic removal of major nutrients. ...

http/lakes.chebucto.org/cyano.html

Blue-greens in freshwater lakes
Unicellular and filamentous blue-greens are almost invariably present in freshwater lakes frequently forming dense planktonic populations or water blooms in eutrophic (nutrient rich) waters. In temperate lakes there is a characteristic seasonal succession of the bloom-forming species, due apparently to their differing responses to the physical- chemical conditions created by thermal stratification. Usually the filamentous forms (Anabaena species, Aphanizomenon flos-aquae and Gloeotrichia echinulata) develop first soon after the onset of stratification in late spring or early summer, while the unicellular-colonial forms (like Microcystis species) typically bloom in mid-summer or in autumn. The main factors which appear to determine the development of planktonic populations are light, temperature, pH, nutrient concentrations and the presence of organic solutes. ...

... Most of these conditions are produced by just three blue-greens, informally referred to as Annie (Anabaena flos-aquae), Fannie (Aphanizomenon flos-aquae) and Mike (Microcystis aeroginosa). An oversupply of nutrients, especially phosphorus and possibly nitrogen, will often result in excessive growth of blue-greens because they possess certain adaptations that enable them to outcompete true algae. ...


... Little is known about the percent of blooms that are toxic (up to 25% quoted in literature), and also why a toxic population is produced. A complicating factor is that part of a bloom can be toxic and another part nontoxic within the same lake. It has been suggested that toxic strains may develop only under a particular set of environmental conditions, or that toxin production may be associated with plasmid-mediated gene transfer. ...

(My comment - also, recall above section on fungal/bacterial/viral pathogens...)

http/fig.cox.miami.edu/Faculty/Dana/cyano.html

... Cyanobacteria may be single-celled or colonial. Depending upon the species and environmental conditions, colonies may form filaments, sheets or even hollow balls. Some filamentous colonies show the ability to differentiate into three different cell types. Vegetative cells are the normal, photosynthetic cells formed under favorable growing conditions. Climate-resistant spores may form when environmental conditions become harsh. A third type of cell, a thick-walled heterocyst, contains the enzyme nitrogenase, vital for nitrogen fixation.

Heterocyst-forming species are able to "fix" nitrogen gas, which cannot be absorbed by plants, into ammonia (NH3), nitrites(NO2) or nitrates (NO3), which can be absorbed by plants and converted to protein and nucleic acids. The rice paddies of Asia, which feed about 75% of the world's human population, could not do so were it not for healthy populations of nitrogen-fixing cyanobacteria in the rice paddy waters.


Found in almost every conceivable habitat, from oceans to fresh water to bare rock to soil, cyanobacteria produce the compounds responsible for "earthy" odors we detect in soil and some bodies of water (such as those being cyanobacterially cleaned at water treatment plants). The greenish slime on the side of your damp flower pot, the wall of your house or the trunk of that big tree is more likely to be cyanobacteria than anything else. Cyanobacteria have even been found on the fur of polar bears, to which they impart a greenish tinge! ...



And people wonder what's 'wrong', that it sometimes appears in their tanks...

I found this, below to be of interest, so have included it in case anyone else does.

Of more importance than the quotes copied below (which happen to coincide with my personal experience and therefore seem reasonable to me) is the fact many people have had entirely different results in trying various things, because not only may different 'algae' potentially be involved, but a multitude of variable factors within even the same tank at different times or circumstance.

And the discussion accessed through the URL given below, while dating from some time back, covers a fair bit of ground and differing experiences and approaches.

http/www.thekrib.com/Plants/Algae/cyanobacteria.html

... First a few things NOT to do (my own, very personal,
experience).

If you have an established infection, do not try to
get rid of it by turning the lights of. Most likely this will
get you into more trouble. Your going to kill of the "good"
algae and the plants, but the blue-green bacteria is going to
return when you turn the lights back on (usually more fiercly
than before). ...

Tony Clementz
Dept. of Microbiology
University of Lund
Solvegatan 21
S-223 62 Lund
SWEDEN

... The method is pretty simple. Don't try to kill the bluegreen algae.
Instead, combat it by encouraging the growth of competing plants and green
algaes. Identify extreme conditions and fix them - give your plants the
best chance to fend for themselves.


Roger Miller


And please do bear in mind that the organism you're fighting practically invented life as we know it, and has survived billions of years in even the most hostile environments.

If it couldn't possibly survive in your tank, neither could anything else.

 

[aaronnorth]

Yes my answer is a little confusing. While ammonia is a nutrient, not many of us see it that way (and most of us know this is one of the main causes of algae), as we usually dose nitrates for the nitrogen, and if we do not dose enough, the plants will not grow, and therefore algae - or cynobacteria - can get a foothold.
and most of the causes (dirty filter, organic matter) cause ammonia spikes.

Low flow/ poor circulation is also another cause.

Some interesting information you have posted there too, although i dont 100% agree with this quote:

If you have an established infection, do not try to
get rid of it by turning the lights of. Most likely this will
get you into more trouble. Your going to kill of the "good"
algae and the plants, but the blue-green bacteria is going to
return when you turn the lights back on (usually more fiercly
than before). ...

If you dont do a blackout then how are you going to get rid of it? Easiest way is to get rid of it, then fix the cause. Plants are not killed in this short amount of time anyway, they be get knocked back a bit, but nthing ti worry about.

 

[Syphoniera]

Yes my answer is a little confusing. While ammonia is a nutrient, not many of us see it that way (and most of us know this is one of the main causes of algae), as we usually dose nitrates for the nitrogen, and if we do not dose enough, the plants will not grow, and therefore algae - or cynobacteria - can get a foothold.
and most of the causes (dirty filter, organic matter) cause ammonia spikes.

Low flow/ poor circulation is also another cause.

Some interesting information you have posted there too, although i dont 100% agree with this quote:

If you have an established infection, do not try to
get rid of it by turning the lights of. Most likely this will
get you into more trouble. Your going to kill of the "good"
algae and the plants, but the blue-green bacteria is going to
return when you turn the lights back on (usually more fiercly
than before). ...

If you dont do a blackout then how are you going to get rid of it? Easiest way is to get rid of it, then fix the cause. Plants are not killed in this short amount of time anyway, they be get knocked back a bit, but nthing ti worry about.

Quote: 'Yes my answer is a little confusing. While ammonia is a nutrient, not many of us see it that way (and most of us know this is one of the main causes of algae), as we usually dose nitrates for the nitrogen, and if we do not dose enough, the plants will not grow, and therefore algae - or cynobacteria - can get a foothold.
and most of the causes (dirty filter, organic matter) cause ammonia spikes. ...'

But it's only confusing for those who don't yet happen to have even a vague understanding of how BGA (or various forms of true algae) functions, and makes perfect sense otherwise.
The quoting of info wasn't only because it's interesting in itself, but because if there's no general understanding of the blue-green nuisance, it's a lot harder to sort out why and get rid of not only it but the potential reason( s ) for its sudden appearance/rapid growth - and there could, as you point out, be far worse results from the circumstances causing an overgrowth than from the algae itself, which may actually serve as a warning of other issues.
And even if the OP knows all this inside and out, new people/forum lurkers may come across the information quoted and have things suddenly fall into place.
People don't tend to mention the history and complexity of the organism, and it may not occur to the newer or more casual aquarium-keeper to look this up generally.
And if, like so many other commonly occurring conditions, it's been too often [not in this case, of course] essentially stigmatized as necessarily a result of sloppy, careless management of a dirty aquarium with neglected fish, new people may even be too embarrassed to ask about it, so it certainly doesn't hurt to counteract this with a variety of information from sources not generally quoted in example.
Aquariums are not and cannot be sterile, they're made to support life - we just typically want only very specific life in there...
And circumstances/causes can vary so greatly that some very different strategies have been successful for different people, and even for the same people in different tanks.

Another point is that since many aquarium plants much prefer ammonium to nitrates, with luck and enough plants, resident algae may be kept starved to a minimum and never become a major problem.

http/www.aquabotanic.com/plants_and_biol..._filtration.htm

But in the high-tech planted tank, of course, maintenance and, as a result, conditions, are entirely different from those of us who may add a few root tabs to inert gravel/sand and dose a bottled patent ferts mix, as in the former case, nutrients are carefully measured to produce plant growth far in advance of that otherwise achievable.
So both basic tank conditions and the perspective of those using different methods may affect results/strategies in multiple areas.

Quote: '... Some interesting information you have posted there too, although i dont 100% agree with this quote:

If you have an established infection, do not try to
get rid of it by turning the lights of. Most likely this will
get you into more trouble. Your going to kill of the "good"
algae and the plants, but the blue-green bacteria is going to
return when you turn the lights back on (usually more fiercly
than before). ...

If you dont do a blackout then how are you going to get rid of it? Easiest way is to get rid of it, then fix the cause. Plants are not killed in this short amount of time anyway, they be get knocked back a bit, but nthing ti worry about. ...'


Actually, neither do I 100% agree with that portion quoted, although the principle fits with results I've had.
Plants aren't usually killed, maybe not even set back too much if in good condition but - you're a plant expert with phenomenal planted tanks.
Your plants will be in top condition, because you know what suits your tank conditions as well as your personal taste, and you can tell at a glance what to dose when, ideal lighting, etc. because you've got the experience and knowledge many of the rest of us lack.
Your perspective - as well as plant conditions and their assisted ability in recovery - is bound to differ from those of us who aren't plant experts, although here, of course, I speak for myself, rather than the OP.
And all I can speak from is my own rather limited experience and what I've read/heard.

So, while I did feel a bit silly suggesting alternatives under the circumstances, it occurred to me that the very fine layer noted by the OP was quite similar to that of a problem I'd encountered in one tank and which was dealt with quite easily, (unlike that in another problem tank which was actually due to be shut down some time ago,) and that removal of this top layer and the addition of more plants might form an option which would not risk setting his existing plants back.

As stated, I developed that BGA problem from plant melt - so I, personally, would worry about setting plants back, which may or may not be a consideration to others, in a situation where a BGA problem already exists.
Because Cyano is evil about coating plants, and where it already lurks it doesn't seem to take much visible (if sneakily concealed) dead plant matter to trigger what can be an amazingly fast-moving boom...

Probably not in your carefully monitored and balanced tanks, though, which is, again, where the different perspective comes into play.

And the O P no doubt has a different one again.

Mine is also one where a half-dozen of my (entirely and extremely low-tech) tanks (so far) house bettas and have limitations on levels of current flow as well as low nitrates.
As I only use a bit of Flourish after waterchanges, and was unable to obtain any for a while, some of the non-earth-sustained plants in the non-Walstads crashed rather badly after a while - starting, of course, by dropping mushy leaves near the back wall behind/among concealing plants and triggering a fair-sized area of cyano, although this occurred in two larger, non-betta-containing tanks with relatively strong filtration, as well as the one problem tank.
I do tend to think of an increase in plant mass (and manual cleaning) as solving this problem (if restricted to specific, accessible areas where this can be easily done, as by sucking up a thin layer off the top of the substrate in a limited area for cleaning and return, with due awareness of the potential for ammonia spikes from the removal of too large a section of beneficial bacteria-bearing substrate) as it worked so well for me, even if I personally would still use a black-out for various other algae issues.
Although the point must also be made that plants are likely not actively sucking up ammonia at that time, just when dying algae is producing more under blackout conditions - along with that of the ability of various types of BGA to survive virtually anything normally encountered in nature only to reappear when conditions are better.

There are a number of elimination options which have been used, successfully by some if not others, due to the variations already noted among algae types and tank conditions.

Personally, when I'm dealing with a problem/subject, I generally like to read through a multitude of sources and get as much info as I can - as you may have noticed, I tend to buttonhole everyone within range when I come across something I think is of interest or worthy of consideration.
Unfortunate for them there's such a lot, lol, as not everyone shares the same notions of what constitutes 'cool info' or areas of concern.
But one never knows which bit of info may be of interest or use to whom, whether at the time or down the road.
And I like to try to establish basic principles by which means I can (hopefully) sort out things generally.

In the case of the OP, he apparently has the beginning of a problem, with a very fine layer of BGA on the surface of sand grains in some areas, which could be blacked out or removed, washed and returned and planted, or whatever - but what exactly is/are the issue( s ) in this case encouraging this problem to arise?
My problems with BGA have been plant-related, so, as stated, I tend to think of siphoning out any dead vegetable matter along with obvious BGA, and increasing plant mass, and have had other algae problems very obviously related to the wrong light for the tank rather than an issue of 'too much'.

Some plant lights do seem to actually slow plant growth and encourage algae.
So, regarding the OP's tank, is any problem in this area more likely the fact of the amount of light in this case, or of the wrong light for the tank, since he'd specified this problem already?
I was rather hoping you'd comment on that...

The OP added:

'... EDIT: Some more info. I actually have some brown algae in the tank (diatoms). The tank stats appear to be fine - though I have no test for phosphates (can phosphates cause brown algae?) This leads me to think it is a lighting issue. I that sometimes low light can cause brown algae.

Additionally my plants aren't growing very fast. They seemed to have really slowed down since I added the Aqua-Glo light. So right now I am considering adding more light. Thing is - do I replace my oldest light-bulb (the one that came with the tank) or do I add an additional third light bulb? ...'

I know nothing of lighting - but when that happened to me in one tank I exchanged the offending new plant light for another slightly less unsuitable light and watched things improve.
The manufacturer may say their light's good for plant growth - but if it doesn't appear to be good for the plants in the tank it's in, should results be taken into account, or at least tested by process of elimination?

That 2-hour siesta period taken between 4 hr. lighting periods should reduce algae growth, from what I've read.
The algae appeared several weeks after the addition of plant tabs - coincidentally or not, the problem area in my tank which was addressed by top-layer substrate removal and replanting was also in an area disturbed by resetting plants (which were also shedding fragments of mushy leaves) over 3-month plant tabs, and I rather more than suspect that some of whatever remaining nutrients were close enough to the surface to feed the BGA as well, although the problem cleared as stated.
(The plant tabs had been added for plants which probably needed higher light, and were initially replaced by ones which were essentially water column feeders...)
In the OP's case, according to the photos, there are no plants in the area affected.
Could fragments of nutrients be sifting up and around through the sand to nourish BGA?

There could be a lot of factors involved, and all I know for certain is what seems to have solved similar problems in various of my tanks.

So viewing things overall, and apart from the blackout, based on the excellently informative opening post given by the OP, what are the problems that should be tackled in the OP's tank, and how?

What's the OP's perspective on this?

Or was the whole thing effectively cleared up by the time I posted this monster, lol?

 

[drobbyb]

Holy cow! Very interesting.

 

[aaronnorth]

I like how you look at things from a different perspective, and asking questions that generally do not seem to be asked To answer some of your/ OP's questions (if i can find them all lol)

'... EDIT: Some more info. I actually have some brown algae in the tank (diatoms). The tank stats appear to be fine - though I have no test for phosphates (can phosphates cause brown algae?) This leads me to think it is a lighting issue. I that sometimes low light can cause brown algae.

Diatoms are common in new setups - how long has the tank been running? Due to the new setup and fairly unstable bacteria, and the possible NH3/ NH4 presence, this is thought to be the main reason why diatoms occur in the first few months - low light is said to be a cause, however, i struggle to see why only this algae would pounce on this situation where the plants would not be growing to their full potential, IMO, you would get more than just diatoms. Silicates in the water (and sand) are also said to be a possible cause, but again, i do not belive this as popular aquarium sediments are constructed of inorganic silicate compounds, ADA Aquasoil is a type of Phyllosilicates - these will remain inthe substrate for a good few years, but diatoms do not stay for those few years... Diatom algae use silica to build their cell walls, it is not a cause.

Additionally my plants aren't growing very fast. They seemed to have really slowed down since I added the Aqua-Glo light. So right now I am considering adding more light. Thing is - do I replace my oldest light-bulb (the one that came with the tank) or do I add an additional third light bulb?

How long has this bulb been in situ? It is said that plants can take time to adapt to the new light. But we need to know more onformation so we can cancel out possible factors:

tank size?
Lighitng ('T' rating, watts?)
fertilisation?
CO2 or carbon supplement?
Plant species?

Some plant lights do seem to actually slow plant growth and encourage algae.

I have never heard of plant lights do this, and see no reason why they would, although i have heard about actinic/ blue coloured tubes encouraging algae growth, and i believe the aqua-glo is an 18 000k tube? I used to have a planted tank with 2 of these tubes, but my plants grew fine and there was little algae.

I know nothing of lighting - but when that happened to me in one tank I exchanged the offending new plant light for another slightly less unsuitable light and watched things improve.
The manufacturer may say their light's good for plant growth - but if it doesn't appear to be good for the plants in the tank it's in, should results be taken into account, or at least tested by process of elimination?

It has been proven that plant growth tubes are a waste of money, they do nothing to help plants grow. Very few if any aquatic plants ever see full spectrum midday sun, since they grow under the canopy shade and under murky waters in the rain forests of the world, rendering the value of Kelvin temperature or of full spectrum out. No bulb even comes close to the spectral distribution of the sun. Having a few peaks in a few narrow bands does not approximate the sun in any way shape or form. The term "Full Spectrum" is merely another marketing term used to suck people in. The Kelvin values of bulbs as well as the "best" term have only to do with what you like to see, not what the plant is capable of assimilating, so what we should be looking for is a good CRI (colour rendition index) which basically means choose a tube which shows off the colours of the plants & fish.

That 2-hour siesta period taken between 4 hr. lighting periods should reduce algae growth, from what I've read

Again this is false information, algae is one of the most adaptable living organisms in the tank, having a siesta period can actually damage the plant growth rather than algae growth!

Could fragments of nutrients be sifting up and around through the sand to nourish BGA?

I doubt it, it would be more of a case that that area gets more light than other parts of the tank due to the coverage of plants.

So viewing things overall, and apart from the blackout, based on the excellently informative opening post given by the OP, what are the problems that should be tackled in the OP's tank, and how?

Firstly we need to know a bit more about the tank, so lets go back to the causes -
low nitrate - 25ppm is fine, so we can cancel this out.
dirty filter - when was the last time you cleaned it? Does it have what you would call 'excessive' waste in it?
flow/ circulation - in a planted tank, we aim for minimum 10x turnover, this not only ensures that CO2 & nutrients are deliverd to all areas of the tank, but also ensures that dead spots are minimized (algae cant grow aswell if there is too much flow) and also makes sure there is no organic matter in the tank - which rots * produces ammonia which can lead to other types of algaeaswell. What filtration system do you have? And do you have any extra flow coming form anywhere like powerheads etc?

I have answered the questions as best I can, if there is anything else then please ask, i may of missed some bits lol!

 

[Syphoniera]

Never mind the poor OP, I probably took up half your evening, lol.
I've already made a couple of very lengthy posts, so I won't take up any more more of the OP's space than avoidable - but boy, you've made some interesting points!
And I guess it would make sense that plants might need to readjust to different lighting, which is something that never occurred to me.
But I doubt I, personally, would buy any more plant bulbs, anyway, not that I could afford the spiffy types - as a broke, low tech person going for cheap alternatives, I'm now quite happy with CF bulbs, as my plants seem to be.
Gonna shut up and go away now, before another lengthy post occurs.

 

[jnms]

What a delight to find all this information, many thanks for it! It's really appreciated!

To give more information, these are the further changes I have made:

- Cleaned the filter media (ashamed to say this was the first time I have done this in 3 months - it was pretty bad)
- Removed the offending BGA
- Removed the plant sections containing the Brown Algae
- Added 5 Corys which are now turning the substrate over pretty nicely
- Added some more plants
- Left the lights off for 3 days (not a true black-out, but it seems to have helped a lot)



As of now, the BGA is almost entirely gone. Though there is some there, and it will probably increase if left unchecked. As Syphoniera pointed out, the BGA is occuring at the front of the tank where there are no plants. The current here is good as it always washes the fish waste away. Also the substrate is cleaned at least twice a week.

A few of the Amazon Swords I have at the back of the tank are disintegrating, I am going to remove these entirely. Rest of the plants appear to be fine.

There is some fish waste stuck among the base of the more heavily planted areas of the tank. How do you normally remove this? It is difficult to get to with the vac. without harming the plants.


Some further information on my tank:
- Tank size 180ltr
- Fluval 305 with 1000ltr per hour turnover
- Interpet PF3 with 800ltr per hour turnover (only recently added)
- There doesn't appear to be any dead spots in the tank
- Adding yeast based CO2. I know the tank is a little large for this, but based on the affect it has on the Ph (from 7.9 down to 7.1) at least some CO2 is getting into the water. The Interpet filter acts as the injection, meshing the CO2 bubbles up to a very small size, then projecting them around the entire tank.
- Lighting is 2x 30w T8 bulbs. First bulb is Aqua-Glo rated at 18,000k. Second bulb came with tank, I have no idea what it is.


Here is a photo of my tank to give a better idea of its layout:

Plants:
Cabomba caroliniana
Cladophora aegagrophila (moss balls)
Echinodorus quadricostatus
Egeria densa
Limnophila aquatica
Vallisneria
Hygrophila corymbosa

I have added a few more plants since the photo was taken, so it is now a little more densely planted. I know some of these plants need more light than I have, I am learning as I go.

Nutrients: Tropica Nutrition+ Capsules
Tropica Nutrition Liquid (5mg a week - only just started this so wanted to see its effects)
I am considering using dry salts

The plants which have really slowed in growth since the new light are the Cabomba and the Swords (the swords just seem to be dying, always disintegrating). Rest of the plants grow nicely, especially the Egeria. Thinking about it now, I added the 2hr siesta only shortly before the new light. Should I get rid of the siesta and just have the lights on for 8hrs straight?

That's about all the info I can think of for now. Thanks again for all the great replies!!

 

[aaronnorth]

Should I get rid of the siesta and just have the lights on for 8hrs straight?

While it would benefit your plants better, it may not be the best reason dur to the DIY CO2 system, as it is just as important to keep CO2 levels up. If you run an 8hr photoperiod, and the CO2 starts to drop by the end of the day, then you could get algae's such as BBA occuring.

The chioce is up to you, you could experiment for a week to see what happens.

Syphoneira, I get my cheap at lampspecs http/www.lampspecs.co.uk/Light-Bulbs-Tub...uorescent-Tubes

with colour references: http/www.theplantedtank.co.uk/lighting.htm