Need help with Sump Design

[djcanis]

I posted this in the Newbie section, cause thats what I am... But havet gotten any feedback. So I will double post and throw it around in here.
Ok, here is the basic design for my sump. The first compartment on the right with the intake line will be live rock, a 4 inch sand bed and chaeto, not calpurea, I am getting the 2 confused quite often. Any suggestions on what should be in the second compartment besides my heater and a phosban reactor? Or should the phosban go after the skimmer on the tank return? Is there a benefit to using the phosban reactor over some type of carbon filled box in the return line? Also, I am using pvc piping instead of tubing. Am I ok using the pvc cement and primer as in residential plumbing or is there something that is meant for reef tanks?
Here are a couple pics as the tank stands now. As it stands now, I have 40lbs of base rock and about 80 lbs of LR. I added about a quart of live sand to seed the 90 lbs bed I have. Still waiting for the water to clear to arrange the rock. That has been the biggesty challange. THe rock now has a thick layer of sand silt, and I have no idea how to clear it off without clouding up the tank. My idea was to set up a coupel of 20 gal rubbermaids with water, powerheads and heaters, pull the rock from the tank, rinse them in a 5gal bucket of tank water and put in the tubs till the tank clears, then arrage. Anyone have an easier way? Will this cause die off, the rock will only be out of the water 10 to 15 seconds...
Anyway, here are pics of the tank and the start of the sump, I am gonna start building it tonight... I will post pic of the progress...

 

[dankbardy31]

Real quick what size of tank is it and what size of sump will it be? What are your plans for the tank, i.e. reef, fowlr?

 

[djcanis]

90 gallon tank, I believe the sump box is 25 gallon, but I am not positive, its 24 x 12 x 14. Its gonna be a reef tank, I have a 350wt MH with dual 96 wt T5's and led moon lights. 90lb sand bed, curently seeding, and close to 120 or rock, 40 of which is base rock also seeding...

 

[jimmy40741]

From your pic it looks like you are feeding your return pump with the output from your skimmer. If so, you are looking at some major problems.
What happens if your return pump is stronger than your skimmer pump? You are going to be pulling water out of your skimmer body faster than it is introduced. I've never seen anyone doing this so I'm not sure exactly what's going to happen but I would guess that your skimmer body will fill with air from the top and then your return pump will be sucking air and burn up.
What happens if your skimmer pump is stronger than your return pump? You are going to be introducing water into your skimmer body faster than your return pump can pump it out and all that water is going to flow right up and out of your skimmer cup.
You need to dump the output of the skimmer into the last chamber and drop your return pump into the last chamber.