Planted Tank Guru
Join Date: Dec 2012
Location: Hot Springs Ar. 71901
You are actually doing a great job of keeping out the algae.
You have aprox 3x the amount of light needed for your tank.
This is where I got that number from.
I had a 30L tank(91cm x 30.5cm x 42cm long) and after adding the sub that made it
aproximately 40 cm from the sub for the light.
This tank grew vals just fine with two 91 cm bulbs of T8 with no reflectors.
See if you can just use two of the bulbs. Some fixtures will allow that.
Two bulbs of T5 instead of the T8 that I had in a tank of similar height and yours have reflectors...I think that two will be enough.
The shortest distance between any two points is a straight line...in the opposite direction...