Chiller closed loop

OK I broke down and bought a chiller. I'm evaporating so much water with my fans I have tons of condensation on my windows and will probably get mold if not controlled. Considering the house is 3 months old, the chiller is on it's way. I'm thinking of using a closed loop like I saw at the meeting to hook it up. Here is a drawing:


So one end will suck wter from the return chamber of my sump, and then pump it back into the refug chamber with the macro algae. Do I need a T joint after the wall like in the drawing for air intake? Do I need to have a cap for the T joint? Also with a Mag 9 will I need to prime the plumbing some how, or will it suck the little bit of air and pull the water down?

I want it in the basement so I don't hear it, and the air is cooler down there. I was going to use a combination of PVC and flexible viynl tubing. Suggestions please! Thanks!

The chiller needs 300 gph min and 700 max. I used the head loss calc at RC and i should run at ~550 gph with a Mag 9.5

The beauty of a closed loop is that you'll get most of the rated (0 head) flow for that pump.  The only head losses will be due to pipe friction.  You should be ok on flow.

The tee is needed to prime the pump.  If you drill a hole in the side of the sump you will not need the tee since it will then become self priming.

Yes cap it.  But better then a cap, imo, is put a 1/2" ball valve on top of the tee.  Open the valve, fill, close valve, start up.  Just pushing a cap on might allow air to leak into the pipe (causes bubbles) and a glued cap is too permanent.  A valve will allow you to very easily reprime the pump if you ever loose the level in your sump.

I just finished my closed-loop with a Mag 9 to drive my SQWD, but the principle should be the same.  I did find it helpful to put a ball valve after the pump to help control the flow.  The Mag 9 is so strong that without the valve it was blowing things a bit too hard. 

I found a lot of closed-loop help at Melev's reef web site.

http://www.melevsreef.com/how_to_build.html

I too use the threaded cap at the top of the priming loop.  It is a pain, but the nice thing is that you know it's air tight.  It is also pretty inconspicuous looking hovering over the main tank.  The loop needs to be air tight to keep the pressure up.  Is a ball valve air tight?  Probably close enough.  That would be a great way to go. 

I used vinyl tubing as well for parts of my loop instead of PVC and it worked fine.