Thanks. After looking at the tank top last night, I'm going to go with 4 X 400W's. There are 4 openings in the top so I figured I place one Mh at each. That way I don't have one directly over teh braceing. The tank already has 8 X 55W pc's and I'll change all of those out to atinic. Just wondering if I want to go with 10K or something a little higher like a 12K or 14K. I want to have a nice white blue that's bright so i'm satying away from the 20K's. Maybe I need the 10K's just to get to the bottom of the tank.
I started figuring out and doing some plumbing last night. Right now, the water goes thru the overflow and into a duroso pipe to a 2" drain line. that goes over to the 30G skimmer sump set on the right side of the tank. That will be enclosed when I do the final installation. From there it goes thru another 2" line to the 90 G sump under the tank.
From the 90 sump, it will go into two Iwaki pumps thru a 1" line and into two UV sterlizers. The out put of each sterilizer will feed it's own 1" spraybar set up on either end of the top of the tank. Each spraybar will have 4 rotating sprinkler heads attached to give a random flow thru the tank. Only about 1 1/2" inches of the sprinkler head will actually be in the water so you will not see much of them.
For a closed loop, there will be 2 X 1 1/2" drains in the bottom of the tank. They will T into each other and feed a pool pump that is hooked up to a hayward cartridge pool filter. The out put is a 1 1/2" line that will feed 4 output nozzles mounted in the angled sides of the overflow box. The closed loop wil be run on a timmer set to run only when the lights are on.
With this type of setup, it will eliminate the need for flapper valves in the return line and if there is a power outage, there is no worries about flooding.
I may have to increase the flow of the sump return pumps if the current ones are not big enough for the spraybar setup. If that's the case, then I will trade them out for some Iwakia 100's or something similar.