Oops Forgot About The Lighting Part

[Renate]

CO2 is impossible for it to compensate for light, the plants use carbon, and expire the oxygen.

Well then, I don't why but the only tanks with low light that have thick plant growth have co2.

For my tank I had 3 T8 20 watt bulbs over it and everything was growing spinley. One bulb was rated a daylight bulb and the other 2 were rated plant bulbs. Now I have a 1 T5 65 watt bulb, which is 6700k/10000K, and 1 20 watt plant bulb over. The plants are growing better now.

I just read that the wpg means the light intensity of the light. Thus if you have 3- 20 watt bulbs over a 10 gallon tank the light intensity is only 2. Is this true?

 

[aaronnorth]

Well then, I don't why but the only tanks with low light that have thick plant growth have co2.

really? take a look at some of llj's tanks, she did a beautiful dutch layout in her 8g and i dont think she used CO2 in that.

 

[SuperColey1]

Tanks that supply the required input for the desired output have thick plant growth. In other words miss (or not supply enough) of one element then it doesn't grow as well. In a non CO2 tank with very low light (1WPG T8/0.5WPG T5HO) then dosing can be virtually minimal as the light will drive the plants slowly, therefore natural gaseous exchange at the water surface may suffice (or a little excel/easycarbo) added and an off the shelf fert dosed as the label. This of course means slower growth and dependent on the plants will have the same result as a high light tank just over a much longer timeframe.

This of course doesn't mean that plants will change to red over a longer period. They will stay green and it means that 'carpeting' plants will grow to their natural height. Stem plants may get leggy due to the low light.

If your plants are getting spindly rather than just growing tall they are more likely suffering and weakening. I can only assume that either your previous lights were inferior or not as efficient or that something parameter wise has changed in the tank (fishload producing natural ferts/increase in dosed ferts etc.)

The WPG rule is very simple = Watts divided by US Gallons therefore 60W over 10USG = 6WPG. Important to remember though that this is a calculation based on a T12 (1½ inch diameter) with a reflector. Lights are now more efficient and thinner which has made this rule somewhat a very very rough guide.

Intensity can only be measured accurately with expensive equipment and there are many factors involved if you want to get scientific. Think about it. The intensity at the water's surface will be a huge percentage greater than an unobscured part of the substrate. An obscured part of the substrate will be even less. So where are you wanting to measure the intensity.

For example my current scape has huge swathes of plants half the way down the tank (needle java ferns ties to the redmoor) and therefore most of the plants in the substrate are shaded quite a lot. In fact the only part of the substrate that gets direct light from the tubes is the front 1-2" or so (obviously intentional for viewing)

Think of the process as a human being.
The light is the exercise.
The more exercise you do the more food you eat to replace energy.
The more light you have the more nutrient they need (C is a nutrient as well as your ferts)
When you are full you relax and stop eating. Plants are a little different. Once they have had enough even if the lights are still on they then start to pull in their leaves (close flowers in the garden.)

AC

 

[three-fingers]

Exactly. I don't beleive in the low light/high light plants theory. They will all grow under low light. The only reason for wanting higher light is to achieve different results from the plants.

i.e. If you want to carpet and you want the carpet to remain low then high light is needed. With low light the carpeting plant will still grow perfectly well and healthy but will grow taller.

Also some plants may turn a desired colour under high light. They will still grow under low light just not reach intense pinks and reds.


AC

I don't get this, are you actually saying that you don't believe plants have compensation points? That's a pretty big thing to say...

Or are you saying that all aquatic plants have very low compensation points, and can all be grown in 'low light' tanks? Because that's still a pretty big thing to say that goes against my personal experiance, what I've read on the internet/books and also even idea's I've been taught in school.

 

[Renate]

I now am uncertain about what specs. are important to in choosing a light bulb. The more I read about light the more confused I get. Could someone enlighten me.

For read:
wpg rule applies to 12T bulbs. The wpg means the intensity of light so 2- 20 watts over a 10 gallon tank is only 10 wpg.

CRI or Color Rendering Index
an indication of how close the light is to daylight (full spectrum). Some look for a CRI but read that the high CRI means there is more green light.

Kelvin is more of how your tank will look to you/us and is totally subjective. the lower Kelvin ratings like 3000K will have more red light and a 10,000K will have more blue light. Kelvin ratings of bulbs can fall prey to marketing schemes/hype.

Then there the PAR and PUR specs which I don't see listed on most bulbs

 

[SuperColey1]

3 fingers...I don't se why you bring up compensation points with regard to my comment above. I am saying that I don't believe that the plants we know as high light are actually high light. I do accept that if you want pinks and intense reds that lighting can be useful for this, however some plants get this colour from what you are dosing. The plant still grows and is healthy just not the colour you wanted it. lol.

Please explain more. As I understand it from the brief explanation in your link it is talking about photosynthesis reaching and equal point in respirations between O and CO2. I am not talking about changing the growth rate of the plant. I am saying that the 'high' light plant may actually have sufficient light within the low light range. It will still be photosynthesising. I am no scientist. Much more of a theorise, the try it, then assess why whatever happened.

Renate....What is important when choosing a bulb is trial and error. CRI and Kelvin are more for your eyes than the plants. Just go for something within the 4-10K range in a combo that gives an appealing colouration to you.

If you have sufficient light then the plants will be OK. Full Spectrum is one of the 'marketing hypes'.

PAR and PUR are the best way to measure light within a tank but it is a very expensive method. Unless you have access to good equipment then just trial and error with standard bulbs (without the aquarium word on their packaging) then carry on with what you find best. You will get 2 or 3 tubes for the price of an aquarium branded one so get the 2 or 3 first time. You spend the same amount. Next time you will know which combo you like and will spend a third.

WPG rule is simple as. 2 x 20W = 40W. Over a 10USG tank you have 4WPG. For each step up the tube types (assuming reflector) then assume you have the equivalent of much higher to the point where 1WPG T5HO can be equivalent to 2WPG on the WPG rule. There is no research as such on this subject. Just that as people have progressed through the lighting scales over the years they have found that they can grow much faster with the same wattages.

Check out this webpage on lighting. Its a much better explanation than I could ever give:
http/www.theplantedtank.co.uk/lighting.htm

AC

 

[three-fingers]

3 fingers...I don't se why you bring up compensation points with regard to my comment above. I am saying that I don't believe that the plants we know as high light are actually high light. I do accept that if you want pinks and intense reds that lighting can be useful for this, however some plants get this colour from what you are dosing. The plant still grows and is healthy just not the colour you wanted it. lol.

Please explain more. As I understand it from the brief explanation in your link it is talking about photosynthesis reaching and equal point in respirations between O and CO2. I am not talking about changing the growth rate of the plant. I am saying that the 'high' light plant may actually have sufficient light within the low light range. It will still be photosynthesising. I am no scientist. Much more of a theorise, the try it, then assess why whatever happened.

Because you still seem to be saying that all of the aquarium plants we classify as 'high light plants' don't actually need this high light to be maintained, and that the high light is only needed to induce colours and/or more compact growth. This may be true for a few of them, but definitely not for all of them.

If it was true, that would mean that all of these 'high light' plants actually have very low compensation points to be able to gain or even just maintain biomass under relatively poor aquarium lighting.
Given the vast number of aquatic plant environments in nature with much higher light intensities than our aquariums, I find it very unlikely that all of these 'high light' plants do have such low compensation points - it wouldn't make sense for a plant to be adapted to cope with such low light when it receives much higher light intensity in nature.

'Growth' is not the same as gaining biomass, 'growth' is just a general term that means gaining in size, which could for example just be cells getting longer (think of it as them stretching out rather than adding molecules). Biomass is basically the dry mass of the plant.

A 'high light' plant can be growing straggly through cell elongation and using up stored energy, but in using up this energy it is losing biomass and because it's compensation point is not being met it's not gaining any biomass back despite that fact it's still photosynthesising. The plant will eventually run out of energy and die - how fast this happens depends on how much it's compensation point is being missed by.

This is seen when something like Heteranthera zosterifolia is put in a low light tank - it will just grow spindly and die because it has a high compensation point.

Whereas something like Hemianthus micranthemoides has a relatively low compensation point, so will not die in lower light levels. It only grows more compact at high light intensities because light breaks down IAA (and probably other growth hormones depending on which part of the plant it is).

 

[SuperColey1]

I see what you are saying now.

I am not implying that someone put 0.25WPG over a tank and expect growth of some kind. What I tend to imply is that the generalisation of 2WPG is needed to grow 'medium to highlight' is not needed wether they actually are 'medium to highlight' at all.

Firstly with advances in lighting since this generalised 2WPG standard was given it means that people bang on about it all the time and put up 2,3,4WPG of T5HO over their tank and it just isn't necessary. When I get some Rotala Macrandra in the week I shall plant it in my tank, not to keep as I like my green and browns but just as an experiment.

What I mean is that people talk about 'in nature' but if you look into any stream, lake, river (where tropical plants grow) you will notice several things.

Most of the plants we use do not look like the same plant in an aquarium due to a couple of things. One is that in a natural ecosystem there is not the controlled and plentiful supply of every nutrient (including CO2) and the plants do not look as healthy as you see in a well balanced planted tank. Lots of deteriroation, lots of algae etc.

Secondly you don't see many if any plants in the centre of these streams, lakes etc. They grow at the edge where they are more often than not shaded by trees or other plants overhanging the bank. People are always saying we cannot replicate the intensity of natural daylight and indeed this is true BUT how intense is the light at the edges in the shadow? Plants that do grow in the centre of the stream or river do not stay 'low' as they would in a high light tank. They all reach for the surface no matter what type of plant they are.

As I say I am no scientist. I just reason with what I have and make assumptions based on my observations (and sometimes a little trial etc) and also from what I read from others and therefore am always prepared to proven wrong but I prefer practical demonstrations rather than theories. I am not the only one who doesn't go by the 'high light plant' theory. I have no answer really to what it is that makes them grow better within a high light plant nor do the others but I suspect it is more to do with the increased CO2/Dosing that we put into a tank the more light we add into it.

I shall pop down to the shop tomorrow and get some Rotala Macrandra and plant it in my substrate. I will be cheating though and putting it in an open space so it can bathe in the 0.9WPG to its hearts content. lol. If it fails then we have found a true 'high light' plant, although by failing I am not saying not being red will be failure as it in nature it is not likely to red. I mean that if it lasts 2 months and still looks healthy (but probably its natural yellow/peach) then I shall say I am right before removing it to stop obscuring my green/browns. lol.

EDIT : I have now got the Rotala Macrandra. About 6 stem cuttings which I will plant in a few hours along with some Crypt Parva I also bought and then take some pictures. I will start a new thread for this experiment rather than take this one anymore off topic than it already is. Wish me luck. lol

AC

 

[waterdrop]

As always, feel like I'm slowly learning bits of things when I read theads like this. Thanks much for taking the trouble to write out your thoughts and trials on these sorts of the things guys!

 

[aaronnorth]

just a quick summary as some people seem to be getting confused:

Watts per gallon (WPG)

total wattage of light(s) / US gallons = WPG
It is based on T12 lights which are not used (or extremely rare) in the aquarium trade, the most common is T8, then T5. the the lower the number before the 'T' the smaller the tube, which then gives out more light per square inch. Also the more efficient!

T12 - 1.5"
T8 - 1"
T5 - 5/8th inch

Kelvin

This generally means the colour of the tube, lower the K rating, the pinker the tube, higher the K rating, bluer the tube.

<4000k - pink
6700K - green
>11 000k - blue

Colour rendition Index (CRI)

This is what looks good to the human eye, and is what you should be buying.

As long as there is enough light, then dont worry about buying 'plant tubes' etc, an excellent source of cheap tubes can be found here:

[URL="http/www.lampspecs.co.uk/Light-Bulbs-Tub...34Pa38Ta38MaNb0"]http/www.lampspecs.co.uk/Light-Bulbs-Tub...34Pa38Ta38MaNb0[/URL]

 

[andyfitz]

Thank you all for your posts I think I learned a few things. so this is the light I ended up buying I got it off of Ebay but have not recieved it yet tell me what you think.

Also anybody got information on algae and snails. I bought some clown loaches to get rid of the snails they are working on them slowly. Is there any chemical warfare I can use against them? Also I have some type of alagae is looks like black hairs not sure what it is. and good solutions for that?

 

[aaronnorth]

Glo lighting is a good make.

Take a look at the algae guide in my sig, BBA is a sign of low/ fluctuating CO2.

 

[Renate]

Great buy!! The 1 10000K bulb will be enough. They are pricy to replace but the plants do great with that kelven rating. It is used on open tanks but I have mine just sitting on the the hood. With it on the legs less light got to the bottom of the tank. It doesn't fans so I wonder if it will get hot. If so you could just put a small desk fan near it. Mine has fans but are so loud I tuned them off and put a small desk fan near it.

 

[aaronnorth]

the plants do great with that kelven rating

Have you read the whole of this thread

K rating doesnt matter.

 

[SuperColey1]

I would say that using the legs to raise it further above the tank maybe a good thing if indeed it reduces the amount of light into the tank. Must've been a bad bit of research and design if this is true. the legs 'should' raise the light to the ideal height so as not to get splashed, not to be too close to the water and give easy access for maintenance.

What do I know. I screw my lights into a wooden hood. lol (mine are 6 inches above water level)

AC