lighting for my 125 gallon tank
I am in the process of setting up a 125 gallon (72" x 18") tank to be heavily planted. I intend to eventually add my discus, after I have the new tank stabilized. I'm currently trying to sort out my exact lighting scheme, and I'd like some input.
Target water parameters:
pH 6.5, GH 3°, KH 3°, temp 82°F, nitrate <20 ppm, DIY yeast CO2
I was originally planning to use 4x96 watts of compact fluorescents, but I've come across a really good deal on 4x55 kits utilizing the AHSupply reflector, Catalina Aquarium bulbs, and Fulham workhorse ballasts. Not only are these kits a good deal, but I'd like to be able to eventually use the GE 9235K bulbs that everyone seems to love, so I decided to avoid the 96 watt kits. I'm looking at using either 6 or 9 55 watt bulbs. I have the choice of either 6500K or 10000K Catalina bulbs.
All this said, I have two basic lighting issues I'd like help sorting out:
How many bulbs should I use, 6 (330 watts) or 9(495 watts), or perhaps somewhere in between (2 complete rows plus a partial row)?
Obviously, my priority is to get great light to the plants, but I also don't want that pinkish "gro-light" cast on everything. What combination of the 6500K and 10000K bulbs should I use to get a good useful and aesthetic balance; 50/50, 66/33, 33/66, etc? Also, if I force my budget and go ahead and get some of the GE 9235K bulbs, which of the Catalina bulbs should I mix these with and at what ratio?
I’ve also got a couple of other things I’m curious about, for anyone that may have dealt with similar circumstances:
I listed 82°F as my target temp, but this is because I'd prefer not to seriously limit my plant choices. Otherwise, I'd rather run around 84° - 86° for the discus. What would you say is the max temperature I can run the tank without significantly limiting my plant selection?
The canopy I built provides approximately 6” of air space above the tanks glass tops, and is completely open at the back. Should I mount the 2” tall AHSupply reflectors so that they are directly on the glass, or at the top of the air space? Also, will I likely build up too much heat in the canopy such that I’ll need cooling fans, keeping in mind that I’ll be utilizing 330 – 495 watts of compact fluorescents?