Easy to grow plants in 24 inch high tank?

[Golfnut]

Anyone grow plants successfuly in a 90 gallon or 24 inch high tank?

I'm will be using standard T12 bulbs. 4x32 = 128w.

I currently grow plants in an 18inch 45 gallon and it works ok, I'm wondering how it will affect growth if I move all my plants in to a 90 gallon instead.

Will they grow worse since the light needs to go "deeper" into the tank now?

I have vals, najas grass, crypts.

THANKS!

Andrew

[Milan]

In my opinion, the only thing that matters in deeper tanks is the amount of light. If I recall my physics correctly, the intensity of light penetrating water decreases exponentially with depth:

Id = Io*EXP^ (-k*d)

Id = Intensity @ depth

Io = Intensity @ surface

k = absorption factor

d = depth

So, I would run some numbers through this equation to see how much the "Id" changes with the increase of "d" (from 18 to 24"), and factor that into the WPG rule (2-4 W/gal). Making your water clear also helps ( reduces "k").

I'm just being theoretical, ... maybe all this doesn't really have any practical value in fish tanks ...

[Mbuna Ron]

I have had good success with my 90 with the same dimensions growing plants. Most of the plants you mentioned are low light anyways. What made a difference was injecting C02 and a suitable substrate. 2-2.5 watts per gallon with 4 5500+ bulbs should be more than adequate! My tank is overrun with plants and I have to thin it out frequently.

[Garhan]

With this lighting system you have approx 1.43 watts/gallon. But as mentioned all your current plants are relatively low light plants. Or so that is they tolerate lower light levels and will grow likely slowly. Even what is considered a lowlight plant will grow faster at higher light levels. Addition of C02 and a good fertilizing program helps to promote and induce healthier growth.