Really 2 Watts Per Gallon?

[Chris0422]

I have doing a lot of reading about lighting. Does anyone follow the 2 watts per gallon rule any,or does everyone use it because its easy. It that for t12's, t8's and t5 HO's. How could it be the same for all three. And what about different tree tank depth? I've just been trying to decide on lights and can't decide.

 

[Ps3Steveo]

It was a rule for T8's really, what are your tank dimensions and are you looking to use CO2?

 

[RossC]

The 2W rule is kind of outdated now, especially as your using HO bulbs. The only really meaning full way is to use a PAR meter to measure the PAR strength of you lights but they're not exactly cheap

 

[frapadoodle]

Tank depth, plant type, and substrate also play a factor.
The deeper the tank, the lower the light at depth. Especially if water is stained with tannins. As well as light placement.
The higher the lights above the tank, less light reaches lower depths.
Also a darker substrate reflects less light.

 

[Chris0422]

My tank is 4ftx12"x22". I have a 2 bulb 48watt t5 HO fixture over half my tank. That's the only side that is heavily planted. The other I have regular lighting with mostly bog wood and moss so my cats can relax a bit. I am at just about 2watts per gallon if I were to divide my tank in half since I am only heavily planting half. I am more worried about one fixture penetrating the lower levels of my tank.

As for co2 I have only ever used it once in the past. I usually have a good amount of fish and have never had any issues with my plants not tacking off. So no I do plan on using it to start but will adjust if need be.

 

[phantomlink]

The rule you really want to follow for lighting is the PAR system I've found, it gets really technical though and I dont really understand it yet

 

[frapadoodle]

I prefer the if my plants grow I got it right, but I have not gone down the CO2 road yet.

 

[Paradise3]

When I had my 3ft planted tank(36"x12"x15" - LxWxH) I had 78watts of lighting on it. The light unit was a 4ft long Juwel T8 Light Unit with 1x 40watt Hagen Power-Glo T8 and 1x 38watt Juwel Day-Lite T8. This essentially meant I had almost 3.3 watts of lighting for my tank accounting for water displacement of plants, fish, ornaments and gravel.

 

[Chris0422]

I'm going to have to say I like if the plants grow its right method.