Do not place the tank in front of a window or least don't let any sunlight shine through into the tank. This is fuel for algae to grow and probably won't help corals any more than a lighting system. You can afford a MH
system for only around 275 (pendant) or even under 200 (DIY
retrofit). I've gone through 3 lighting systems and I would have saved money if I went MH
off the bat. PC IMHO
are very bad, they aren't effient in the way they are built and more reflectors don't reflect that much more light into the tank. Given with enough PCs you can keep some of the harder to keep stuff, but you'll be paying big bucks. I had 2x55 watters on my 3' 50 gallon tank and they blew. Hard to believe but my shrooms
didn't even like that light (50/50s).
Went to T-5 HOs. Big upgrade in my opinion but for whatever reason i was still losing some corals (open brain, frogspawn). I had 2x39 w/ great reflectors AND PCs with it and was still losing some of the LPS
corals. My shrooms
were opening larger than with the PCs alone however.
Jumped to MH
this last week and LOVE it! I have a hanging pendant, 10 inches above the tank about 12 inch over water and it doesn't heat up the water all that much. All of my corals are larger than ever and give off better color. Shrooms
have gotten huge! And I just added a couple of Montipora Digitatas got my tank and they are acclimatingly nicely. I can see some small polyps spout out.
Assuming your tank is 4' in length, you'll be putting out at least 200 for 2x96 watters (if its a fixture vs retro). Each bulb when they need replacing will cost around 70 bucks. And at 4' in length, you might have to get 4x 65 watters, equaling more in cost to replace the bulbs.
Making the move to get MH
off the bat will seem expensive but I believe its one of the most important purchases to maintain a reeftank.
About the substrate, DSB
will lower nitrates after its been setup for quite awhile, CC
is a big no-no, and BB isn't too bad, I run a BB because I love the flow of water I can obtain without causing a sandstorm.