Lighting for planted tanks: Quantity or quality?

[illumnae]

I've seen WPG being used as a standard for the amount of lights required for planted tanks, and i've also seen people emphasizing the need for good types of lights and/or individual reflectors to increase penetration/spread/what not. so how are the 2 interrelated? if you have individual reflectors on t5ho lights, would that mean you need less WPG than say a shared reflector PL set, or even a shared reflector t5ho set? where does the overlap lie, if there is even one at all?

is 2.0 WPG t5ho with individual reflectors equivalent/better to say 3.0 or even 4.0 WPG with lousy reflectors? (assuming the reflectors on the 2.0 WPG setup are positioned such that the light is spread all over the tank)

[catohcat]

I think coming down to the fundamental theory, what counts in is the amount of light energy (with wide spectrum) hits on the leaves' surface. So both WPG & bulb's quality serve this main purpose... Therefore it depends on your aquascape design to adjust these two factors as long as you see all your plant are highlighted & bright =). Ex. if your tank has a lot of woods/hiding places, a few t5HO at different reflection's locations (quality) are needed. While a bare tank (like's Jervis Stone Fomation), one MH will do the job (quanlity).

My 2cents thought, there'r a lot of thing I'm still in learning also.

[Aquaculture]

Interesting question. I'm thinking like which one comes 1st, the chicken or the egg.... very mind bogging. Personally, I would 1st consider the wattage of lights (can be qualtity or quality) needed then the 'throw' distance (quality factor) in consideration of the depth... using way of deciding, I'll go for quality.

[illumnae]

so you would use, say, 2-4 tubes of "branded" t5ho with individual reflectors over 4-6 tubes of "china brand" t5ho with just white paint as the shared reflector?

[dcwk]

My experience. Before, 2.5wpg (China T5HO). After, 1.7wpg (T5HO with parabolic reflectors). Plants in my 2ft deep tank is doing much better.

If your tank is 1ft or 1.5ft deep, then I believe China T5HO should be ok.

[illumnae]

i guess that answers the question quality > quantity!

my tank is a 2ft deep one, was wondering if i should go for 4x54w with individual reflectors for 1.96 wpg or 6x54w china brand for 2.94 wpg

[dcwk]

If your tank is 2ft deep, go for parabolic reflector.