I just got a new 125 gallon setup on CL, well it's not new but it's new to me =) Anyway I am familiar with lighting for 55G tanks in which I have always used a 48'' 2x10,000k bulb fixture 1 actinic, 1 daylight. But I am out of my league here with supplying adequate lighting for this setup. I have never in cased lighting into a canopy, and as I can not raise or lower the lighting I want to be assured I am supplying a sufficient amount of light. I will be dosing EI method, and pressurized Co2 with a 5lb tank and 2 glass diffusers inside the tank when its set up. I'm planning on making a whole lot of MTS and laying pool filter sand on top, then attaching nana anubias, christmas moss, and java fern to a large piece of manzanita I got from PC1. I have 15 3'' discus that will be transferred from my 55 gallon into this tank as well. I read up on some other threads and correct me if I am wrong, but sufficient low lighted tanks allow the plants to absorb the nutrients and Co2 in the water better, and produce some of the most beautiful plants it seems. With this in mind (provided this is correct) my plan is to buy 4x36'' 2x64w T5HO fixtures and then install 2 fans into the sides of the canopy, and add some moonlighting. This should be adequate for a low to medium light setup correct? The canopy actually comes with what I would call standard 48'' and a 24'' fixtures built in, I have no idea what the wattage the fixtures are capable off as I am still pending pickup of the setup. But I am assuming (might I add I am finding when I assume I'm almost always wrong) that these fixtures can not hold T5HO bulbs... Let me know your thoughts, comments, and suggestions. I will post pictures when I get it all setup too, thanks for reading =)