2lucky

Hi, I have a 36W flourescent light for my 107 gallon tank, I bought it when I did not know how much light was required per gallon for effective plant growth- I just bought one that was long enough for my tank.
It is a really bright light so I thought it would be fine for my my plants, but they are barely growing or very slowly.
If I were to get the appopriate wattage for my tank they are all so expensive.
Can someone please explain to me what I should do, I really want a lush green tank and am willing to inject co2.
thanks!

agabr123

do you have just one 36 watt light? if so then that's definitely not enough for you, as that's about .3 watts per gallon. you really need to have a minimum of 1 watt per gallon of light, but it depends on what kinds of plants you would like to keep.

having said that, what kind of plants do you want?

Llama

The usual rule of thumb is 2 Watts / gallon, but then it depends on the plants you're going to keep. Check how much light each plant needs.

2lucky

All of the ones I want to keep seem to be high light plants (like cambomba, vallisnera etc)
But I was talking to my dad and he said that flourscent lights only came in about 40W largest.
The light is sooo bright, if I put the 4 more globes in I need the fish would get glare!
So can you get high wattage lights that are NOT extremely bright?
Thanks

mathas

Not necessarily. My vals did just fine on 1.4wpg, which is hardly "high light".

96W is the largest I've seen.

Since "bright" isn't solely determined by wattage, the short answer is yes. But I'm going to quote from Aquatic-Eden's article titled "Top 3 Mistakes When Starting a Planted Aquarium":

"The standard lighting that comes with an aquarium will typically only grow Java Moss and maybe Java Ferns and very poorly at that. If you like ugly, lanky, unhealthy plants go ahead and try it. No matter how bright it may look, it is not enough light. Plants only use specific colors of light, usually in the red and blue ranges. Humans perceive green as brightness. Therefore, what appears bright to us may not actually be helpful to plants."

The point is that plants don't care how bright it looks... they need energy, not brightness.

If you want to do some reading on your own, you can start here:

http://www.americanaquariumproducts...._Lighting.html
http://www.aquaticplantcentral.com/f...osythesis.html
http://www.thekrib.com/Plants/Tech/lighting.html#10

Franklin

I am not good at explaining it,but you will need a lot more WPG of light if you want to use pressurized CO2.You will also need to be dosing with ferts if you up your wattage to the point you need CO2.
How long is your tank?There are some fairly inexpensive T5 lighitng fixtures that work quite well with low light plants.And I have some vals in a tank right now that is just 1 WPG and they are doing just fine.

2lucky

Thanks for the replies! You explained it to me so that I understand the whole lighting thing alot better.

So I know I need alot more light. Should I go for 4 globes of 50W florescent or what? I don't have stacks of money to throw away so the most economical option would be good. What type of flourescent light should I look for if I want to get 4 globes butnot scare the fish coz it's too bright?

What is T5 lighting fixtures?
and I want about two WPG - that should cater for most plants and I wouldn't need to add CO2??

My tank demensions are about 150cm wide, by 2foot wide and high.
Thanks so much

mr. Clown Loach

look in the DIY section for lighting things