How about some help from local reefers

[jarhead]

Hey guys and gals,
I plan on testing my system for the first time next week and wouldn't mind hearing some tips from local reefers before I flood the house. :o So any last minute advise? You can post your replies to this thread:
http://archive.reefcentral.com/forums/showthread.php?s=&threadid=162958

I hope this is not what you call cross posting.

[jarhead]

The test didn't go that well. I filled the tank to the very top until the water started falling into the overflows. In the basement I filled the refugium and the sump to the top. After the pump was turned on, the tank started filling up and water draining into the overflows where the water was fluctuating somewhat. After a minute or so, the flow stopped completely as though the pump was turned off. We thought that the pump drains the sump too fast and starts sucking air. I tried throttling the pump back, but that didn't help either.
In any case, I don't know what to do next and was hoping that some of the local reefers would be able to stop by over the weekend and lend a hand.

[Corpus Callosum]

I wish I could help but I don't have much experience with that type of stuff :(

[Justjoe]

Originally posted by jarhead
The test didn't go that well. I filled the tank to the very top until the water started falling into the overflows. In the basement I filled the refugium and the sump to the top. After the pump was turned on, the tank started filling up and water draining into the overflows where the water was fluctuating somewhat. After a minute or so, the flow stopped completely as though the pump was turned off. We thought that the pump drains the sump too fast and starts sucking air. I tried throttling the pump back, but that didn't help either.
In any case, I don't know what to do next and was hoping that some of the local reefers would be able to stop by over the weekend and lend a hand.

When you say the flow stopped completely, what do you mean? Did the water stop overflowing the tank to the sump? Did the sump run empty before the tank overflows were going? Water in has to equal water out unless your overflows are restricting the flow back to your sump, which would allow the water to build up in the tank and that would drain your sump. If thats the case, slowing the pump won't matter. If your sump is too small to allow for the head water to build up in your tank, the sump will run dry.
What town are you in? Any digital photos to show your setup?
Joe

[JB NY]

I know we've been going through this on PM but here might be a better place as others can maybe see something that we are missing.

So I've been thinking about this. Maybe it's your refugium that is causing the problem. When I start up my pumps the refugium takes a while, 30-40 seconds, to catch up. Basically the refugium will fill up over the drain and water line in the refug will go up another inch or so. Then the drains lock in, and the refug flushes down to the top of the drain where it stays. During that time the water level in the sump will go down but then starts to rise after the refug catches up.

Try taking the lines from the refugium and put them directly in the sump to test. See if that fixes the problem.

[jarhead]

Thanks to all for their advise. It turns out that my sump is too small for the system and the pump. The sump size is ~24g. Based on my calculations, the return and drain pipes hold ~6g of water which leaves me with ~18g in the sump. Being that I have to leave some room in the sump for the water to drain down when the pump is shut off, that leaves me with, say, 15g of water. When my pump is turned on, it suck out the 15 or so gallons in no time. Even throttling the pump back didn't help much. That being said, I ordered a 75g AGA and will use that for my new sump.

I will get rid of the 5g water jug (used for eliminating the bubbles). With the new setup, the water will drain into the old LifeReef sump where it will be skimmed and down into the new 75g sump. The pump will be relocated down next to the new sump.

http://a8.cpimg.com/image/6C/56/17144428-fe44-0200019B-.jpg
http://a9.cpimg.com/image/23/CF/17179939-beb3-02000156-.jpg