[crocodylus]

Here are a few questions I’m mulling over… I want to populate my 100G (60”Lx25"Hx16"W) tank with some anubias, vals and swords. At the moment I have a 36” All-Glass fixture with 2 55w CF bulbs (it was a used tank and the light that came with it was like 40w). I don’t want to use CO2 (I do use ferts: flourish complete, flourish excel and K). I want to upgrade the lighting with either 2 24” fixtures or a 60” one.

Q1) is the lighting I have now (1.1w/g) enough?
Q2) would 2 24” with 1 65w bulbs each (1.3w/g) be enough or should I get 2 24” with 2x65W each (2.6w/g)
Q3) would a 60” with 4x65w be better?

Thanks in advanced for the responses

 

[Wasserpest]

Hola, if you are not going to use CO2, IMO you don't want to go past 1.8 or 2 W/gal.

The most efficient solution for this sort of undertaking would be 2x 80W T5 lights. They are not widely available though.

For my 5ft tank I use 4ft T5 bulbs and add a little PC bulb on the ends to prevent dark spots.

If you go with 2x 55W PC bulbs IMO you'll have some underlit areas, since they are only 20" or so of bulb.