need help with sump

[garyw68]

When I first setup my 90 gal reef, I was too much of a newbie to think about overflow and a sump/refugium. Now I plan to put in my sump this weekend using a overflow box that I just received today. Is is a CPR CS90 with a flow rate of 600 gph and is rated for tanks up to 125 gallons. I got it from marine depot so I assumed it was a good buy. My questions are these:

1. what rated pump do I use for this kind of overflow box? I have two maxi-jet powerheads which are rated for 295 gph each. Do I stay close to 295 or more towards the 600 gph?

2. what keeps the overflow/sump from overflowing when the power goes out?

3. Do I use draining hoses or PVC pipes with shut off valves for the overflow and return?

I guess thatââ"šÂ¬Ã¢"žÂ¢s it for now. I am sure I will have more questions during the weekend while Im putting it together.

Thanks in advance.

 

[piranhaking]

the overflow doesnt overflow because once the water level drains to a certian point it is no longer underwater and cant drain. The sump doesnt overflow because it has room for the water that drains out of the pipes and the area above the overflow.

 

[rtmelendez]

I drilled a couple of very small holes in my return line a half an inch under the normal water line, just to make sure I don't get a back siphon into my sump when the power goes out.

 

[thisiscmd]

If your overflow can only drain 600GPH, then you don't wan't to have a pump return more than 600GPH.

Reason being, you don't want your drain to the sump struggling to keep up with your pump. Eventually you'll be running the pump dry at times as it will be emptying out the sump faster than your box can fill it.

Melev, a sump genius, says 4-6x your total water voume is a good flow through your sump.

If you are putting a valve on your return, make sure you tee off and allow water to flow back into the sump as well. You don't want to just put a valve on your pump and restrict flow, forcing the pump to work harder. That will cause unnecessary stress to the pump and wil ultimately lead to failure.

I learned 99% of what I know from Melev's site and others like his...

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

 

[rtmelendez]

I also teed off of my return into my sump, because my pump is too strong for my overflow. I barely have to adjust the valve on the tee, although it does create a lot of motion in the sump.

At first it seemed like it wasn't going to work, because there was a whirlpool thing going on in the sump, and some slurping noise from a little air getting into the line, but it seemed to work itself out. There is still plenty of swirling going on, but it doesn't seem to be affecting anything, and no more slurping noise.