Have you looke dat any of the large tank setups in this forum? I recently started a thread on mine that I purchased as a complete FOWLR setup. Some of these people are right, big fish poop big. Like baby size poop.
My tank is 3' deep and is a pain to reach the bottom. I can't imagine one 4' deep. You'll need some custom made long tongs and scrapers to keep everything clean.
A good filer for just keeping the water somewhat clean is to use a swimming pool cartridge filter. Check out my thread and you'll see one. It flows 5000GPH and I have it set up on a closed loop. I recently found a new style filter cartridge for it that I'm trying out. It's supposed to be able to be cleaned out with just a waterhose. The original cartridge for it, I had to use a pressure washer just to clean it. I did this about every three to four days. So far, the new filter has been in for 4 days and I'm jsut now starting to see a drop in the pressure. With the old filter, it would drop 10 PSi in 3 days and was time to clean it. So far, this one has only droped 3 psi in 4 days.
Another thing is the skimmer, GO BIG. You may want to look into a comerical skimmer from some of the other companies, not the hobbiest one's you've been looking at. My skimmer, though home made, is 6' tall with a reaction chamber of 10" dia. and 5' tall. It's run my 3 Sedra 9000's w/ needle wheel impellers. It does a good job of cleaning up the water I I use Ozone on one of the pumps.
Did I mention that big fish poop like babies?
UV's are also another good thing to have on FOWLR. Even if you go reef, their still not bad to have. I have mine inline with my return lines. It helps keep the water clear. Don't worry about it killing of the good things, I have a TON of pods swimming all around in my tank. Some as big as a 1/2 inch because I have no preadators.
Electric bill's. When I set up the basic system after moving it, I was running two pumps, one spa pump for a return and one pool pump for teh closed loop, three skimmer pumps, 8 X 55W PC lights and a few monitors. My electric bill went up 200 dollars a month, just by adding in this tank. With MH lights, I'd expect another 100 dollars to be tacked on. I'm currently looking for some more efficent pumps as teh two I have, one pulls 9 amps and the other pulls 6 amps. It's hard though to find a pressure rated pump that will flow 5000 GPH at 20+ feet of head pressure and is still efficent.
I don't like equipment in my tank so that is why I have such a larg return pump. You may be able to get away with less if your running streams in the tank.
Here's a link to my setup and some of the equipment.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=630143
Good luck and post some pic's when you can.
