Common Green Algae

[andyG44]

This is the third time this happens in 4-5 years and multiple tanks. As soon as I add a few live plants suddenly the aquarium gets covered in green algae.
 
I have had a plec for a few years he is around 3 inches now but there is only so much he can do. I use a brush to clear the glass, it's very easy, but I can not do much for the white stones and pure white ornaments which are currently white-green!
 
I got a few snails today, I think they are called bladder snails but maybe wrong, I was told they eat algae more than the plecs. So they do, I can see them working hard today, but I do not think they can cut it either.
 
Contrary to another post I read, that live plants inhibit algae, in my case, live plants introduce algae!
 
A method I have heard about is UV light inside the water filter. My current filter does not have a UV lamp but I know some do. Would that eliminate/reduce algae?
 
A sure-fire method I have tried, but very hard to do, is to remove all fish, remove all water, spray the insides with hot water, within 2 days everything white will become white again!
 
In the meantime if you know of a better method please let me know.
 
Thanks
 
 
 

 

[Akasha72]

how many hours a day is the light on and is the tank in any natural light. Excessive lighting can cause algae growth

 

[Byron]

Yes, we need to know the data.  Adding plants is not in itself going to cause algae in the tank (as opposed to on the plants) if none is present without plants, so we need to look at other factors.  Detail your lighting, fertilizers if any, plant species.
 
First, we have to identify the algae.  Here's a site with photos that may help:
http/www.aquaticscape.com/articles/algae.htm
You can click on the photos there and enlarge them.  Once you ID the type, let us know.
 
You mentioned UV.  This will have no effect on algae; it is useful for green water (which is unicellular algae), but not algae growing on surfaces.  And so-called algae eating fish have limited usefulness as most will only eat specific types.  Snails do eat algae, but this is not going to control an outbreak.  Balancing light and nutrients is the only way to bring any algae under control.  And we will get to this with the data.
 
A photo of the tank would help too if you can.
 
Byron.

 

[andyG44]

It is a community tropical tank is 180 litre around 40+ fish filter is Fluval 206 it sits next to large patio door south facing so gets a lot of light. Internal lights in the tank are on while we are awake and there is also other lights in the room anyway. I have read people covering their aquariums but that really defeats the purpose, I wish we do not have to go to those lengths.
 
I have two plecs and a handful of snails. The plecs spend their lives in hiding and the snails as I said are hard at work.
 
Currently the algae is not terrible, I have had worse, much worse with a 40 litre I had also next to patio doors, however I remember it starts when I bring new plants in, maybe a coincidence.
 
If the filter canister contains enough bacteria to support the tank then I could move the fish and plants out and zap the insides with hot water. A simple sprinkle completely destroys algae. A lot of work though and will stress the fish.

 

[NickAu]

 
how many hours a day is the light on and is the tank in any natural light. Excessive lighting can cause algae growth

Am I the only 1 who runs his lights 10 hours a day without any problems?

 

[Byron]

 

 
how many hours a day is the light on and is the tank in any natural light. Excessive lighting can cause algae growth

Am I the only 1 who runs his lights 10 hours a day without any problems?
 

 
I can quickly answer this Nick, by saying that it all depends upon the balance.  When I lived in the condo prior to 2000, I had the tank lights on for 15 hours daily, with no real issues.  But for some reason, now that I am in the house, I cannot go above eight hours or I get a real blosomming of brush algae that just smothers the plants.  One tank is even down to seven.
 
A few summers ago, I noticed that brush algae kept increasing in the summer.  I realized this was likely due to the increased brightness and length of daylight coming in the windows during summer, so the next summer (and for two since) I kept the windows heavily draped.  End of algae.  This shows how delicate the light balance with nutrients can be.
 
I have had algae increase due to too much light, but also too little light; and with too much fertilization, and also too little.  In all four cases, it was because the balance between light intensity and nutrients was out.  Once it is balanced, then we can play with duration, which also factors in to this balance.
 
Also, the plant species and numbers factor in, as does the fish load including size of the fish and numbers.  And the foods added, plus the water changes.  As you can see, there is a lot to this "balance."
 
Byron.

It is a community tropical tank is 180 litre around 40+ fish filter is Fluval 206 it sits next to large patio door south facing so gets a lot of light. Internal lights in the tank are on while we are awake and there is also other lights in the room anyway. I have read people covering their aquariums but that really defeats the purpose, I wish we do not have to go to those lengths.
 
I have two plecs and a handful of snails. The plecs spend their lives in hiding and the snails as I said are hard at work.
 
Currently the algae is not terrible, I have had worse, much worse with a 40 litre I had also next to patio doors, however I remember it starts when I bring new plants in, maybe a coincidence.
 
If the filter canister contains enough bacteria to support the tank then I could move the fish and plants out and zap the insides with hot water. A simple sprinkle completely destroys algae. A lot of work though and will stress the fish.
 

 
Were you able to ID the type of algae from the link I posted previously?
 
My response to Nick's question will explain what we are going after here, now that I've written it.
 
Byron.

 

[andyG44]

It is green algae called "blue green" I think.
 
If live plants (and which) are antagonists (competing for the same resources) then I'd rather have the plants which I can prune when needed.
 
I have 3 live plants and 4 marimo balls.

 

[BiggTexx]

This is not really in response to the algae, but what type of fish do you have?  With 40+ in a 180L (~45 gallon) you sound overstocked, given that a 3" pleco (common?) is taking up over a 1/4 of your stocking level and still growing.

 

[Byron]

We may be getting somewhere.  If it is the so-called "blue-green" it is not really algae by a bacteria, cyanobacteria.  This is always due to high organics, in the presence of light.  And picking up BiggTex's comments, too many fish is the source of high organics beyond what the system will handle.  Pleco, depending somewhat upon species, are well known as waste factories which obviously contributes to organics.
 
When we have the stocking info BT requested, we will know more.
 
Byron.

 

[andyG44]

I have
 
14 guppies
6 galaxy rasbora
2 dwarf gouramis
4 black phantoms
6 neon tetras
4 mature gold barbs
3 mollies
a handful of snails (believe to be bladder snails)
2 plecs, one is 2 years old and around 2-2.5" the other is newer and 1-1.5".
around 20kg gravel of two types (thin and coarser)
3 live plants
4 marimo balls 2"-3" wide
some ornaments

 

[Akasha72]

wow ... lots of fish in only 180 litres and all mid to top dwellers too. I was hoping some of them would be bottom dwellers - cories or such-like. 
 
This is what blue-green algae looks like
 

 

 

 
 
 
This was one of my tanks a few years ago. I got rid of it by completely blacking out the tank for 5 days. No tank lights, no external light. I covered the tank with blankets and towels and just twitched it aside once a day to throw in some food before quickly covering it back up. Once that was done I did a large water change and I've (thankfully) never seen blue-green algae again ... I hope I never do. It's horrible stuff

 

[BiggTexx]

Alright, this is worse than I feared.  According to my observations, you are way overstocked. I mean close to 2.5 times more fish than you should have in that setup.
 
Also, keep these in mind:

• You should have at least 5 Black Phantoms.  Shoaling groups should be kept at 5-6 as a minimum grouping.
• The Black Phantoms are fin nippers, so make sure they are not harassing the guppies
• Photos of the pleco's would help tremendously to help identify them

This may sound harsh, but do you have access to another tank, a larger tank or can you re-home some of your fish?

 

[Byron]

I concur.  Another factor we do not have concerns water changes, namely, how often and how much of the tank volume.  This does impact algae, and cyanobacteria.  Also, the degree of substrate cleaning during the water changes is an important part of cyanobacteria control.  Organics is the cause of cyanobacteria; it needs light obviously, but keeping the organics under control is the issue.
 
And, on the hot water method, this will not work.  Cleaning out the tank and filter will obviously get rid of what's present as the organics will be gone.  But once they accumulate again, the cyano will return.  This applies to problem algae too, for the record.  And such a drastic measure will almost certainly detrimentally impact the bacteria and general biology, making matters even more difficult to control.  Dealing with the cause is the only viable option.
 
Byron.

 

[andyG44]

Hi. The algae or bacteria seems to be under control. The glass surfaces look better. A large, white ornament looks almost white, other white stones and ornaments are not that bad either.
 
Could you please tell me how I can calculate the amount of fish for the tank?
 
The black phantoms are very docile, even hiding a lot, the gold barbs are outrageously energetic chasing each other all over the tank, and as they are mature (had them for years) they are almost the largest fish. The guppies are fun to watch - all males, I was told not to get females. The neon tetras are hanging out with the galaxy rasboras a lot of the time. The two dwarf gouramis both mind their own business (and nip the plants). The three mollies are the most inquisitive along with the guppies and they also nip the plants. All the fish seem to be happy (touches wood).
 
I think reducing the light maybe a good idea and if it fails then I will take more measures.
 
The two plecos aren't that special, one I had for years the other is very recent purchase. They mostly hide inside ornaments and can't be seen.

 

[Byron]

Could you please tell me how I can calculate the amount of fish for the tank?
 

 
There are several factors one has to consider.  There is a "rule" that one still sees now and then, an inch of fish per gallon of water (using maximum mature fish lengths) but this is not at all reliable and I only mention it because you may encounter it and wonder why it isn't the answer.  There is likely a metric version somewhere, but still unreliable.  Fish size in relation to the water volume clearly matters, but this is only the beginning.
 
The tank size has two main aspects: the physical space needed for the fish to be "itself" or "normal," and the volume of water which supports a complex biological system involving fish, plants, many different types of bacteria, and invertebrates.  Fish impact the water chemistry and biology in several ways.  The larger the fish, the more food and thus more waste entering the system.  Fish also release chemicals called pheromones (read by others in that species) and allomones (read by other species).  So the more fish there are, and the more different species, the more "confused" things get, and the fish react which adds even more pressure on the system biologically.
 
Each fish species has specific requirements, and if these are met, the fish will be less stressed which means less impact on the biology and healthier.  The swimming activity level of each species may differ; some are active swimmers so need more physical space, others are sedate so need less space--and the actual size of the fish may not even be relevant with respect to this one issue.  Some fish need a group, others do not.  Each species has a preferred range in water parameters (hardness, pH and temperature) and if this is provided the fish will function more easily and thus impact less on the biology.  The traits of each species may vary, in terms of aggressiveness, and this impacts on the biology.
 
You have some shoaling fish species, which should have a group: neon tetra, black phantom tetra, galaxy rasbora and gold barbs.  The number in each group varies, again because of the specific traits of each species.  Neons can manage with six, as can the black phantom tetra; this is the "usual" minimum, but more is always better.  [If I go into the involved reasons how the number alone significantly impacts a fish, this post will be endless, but I will gladly try to explain it if asked.]  Galaxy rasbora should have a larger group; the profile on Seriously Fish suggests 20 or more.  The Gold Barb is best with eight to ten, or more.  These numbers are aimed at providing the best conditions.  Obviously, sometimes fish seem to manage in less than the best situation, but this can be good or bad in itself.  It is not always easy to see externally when a fish is under stress from something not being to its liking, and it is certainly a situation that should not be deliberately entered into.  This is why we always recommend researching a fish species before acquiring it, to ensure you will be providing the best you can.
 
Jumping to the chase, you obviously cannot increase all these fish to such numbers, and there are other aspects of this too.  Water changes are not mentioned yet, but the more the better when the aquarium is over the safe limit.  I would certainly be doing 50-60% of the tank volume no less than once a week, at a minimum; some members will likely suggest more than this.  And re-homing some of the fish if this is at all possible.  The algae/cyanobacteria, whichever it is, is a sign that the biology is being pushed.  Reducing the light is not the answer, though it may help decrease the algae; but the underlying condition is still there.
 
Byron.