How many 36W PL should i use?

[bettapassion]

I have a 4ft 68 gallon tank, plann to make it a planted, just wanted to know if 6 36W PL enough for the tank?

[David]

hi bettapassion

the guideline to the amount of light needed for a planted tank is 3watts to a gallon....since you know what your total volume is at 68gallons, this means that you will need to have roughly 204 watts.....

6 x 36watts = 216 watts....so this means that your light should be sufficient....

[PeterGwee]

Going by the 3watt/gallon for high light plants, yes, it is enough.

[bettapassion]

I have a 4ft FL light with 2 tubes, I wanted to convert it to 6 PL light and place it in the middle of the tank will that work? Or do i have to spilt into 3 holders for 2 PLs each across the top of the tank?

[vinz]

Yeah you can do that, but I'm wondering if you can fit 6 x 36 PL-L into a 4ft FL holder. Oh, by the way, please read "Cautions when converting FL to PL" in the Aquatic FAQ forum before you do your conversion.

It'll be better if you can spread it out a bit. May be one set 4 x 36 and one set 2 x 36. Three 2 x 36 would give a better spread.