[bongobrian]

Ok I am new to setting up sumps and doing plumbing stuff. I set up a sump style refugium yesterday and I have kind of a stupid question. How do I control the flow of the return pump? Right now I have the system set up with a simple overflow/return design. The problem is, my return pump is pulling more water out of the sump than the amount of water going to the sump from the main tank. I just need to restrict/control the amount of return water. Also I should mention, my return plumbing is a clear, flexible type of tubing. It isn't hard pvc. I'm just thinking I might need to put some kind of valve or additional plumbing in the mix. Any help you guys can throw my way would be lovely. Thanx.

[WannaBeAReefer]

You can put a ball valve in the line and just adjust it to the proper flow... HTH

[mrok12]

Brian,
Plumb the out let with PVC to place a ball valve after the pump outlet also use a union before the ball valve so you can disconnect. Get a slip/threaded coupling and a pve barbed nipple to convert from pvc to flex hose. When my camera charges I will post a pic if you need it.


MROK12

[scubadude]

I agree to a Ball Valve, just make sure you put it on the output side of the pump not the input side. And as mrok stated you might want to put unions for easy quik disconnects. Also I had this problem on my setup too, but it turned out that the overflow takes awhile to catch up (balance out) with the output of the pump.....but with a ball valve you can throttle down then wait 10-15 min then throttle it up a little and keep repeating the process tell you find the correct water level you want to ascertain. HTH

[Reefland]

As the others mentioned, a ball valve on the output side of the pump would work. Another option if your using a HO overflow would be to add another. If the pump is pushing more water out of the sump than the overflow can drain down, the return is greater than the drain. For optimum performance from your pump, make sure your drain capacity is greater than you return.

Good luck,
Scott Z.

[WannaBeAReefer]

I absoultely 2nd Reefland's opinion.

You must have your overflow draining capacity exceed your return's output or you will (eventually) be asking for trouble.

Also, I put check valves on my returns so that you don't accidently syphon your tank if your return pump stops.

[bongobrian]

Thanks! you guys rock. Actually I found a way to fix the problem yesterday. I put in a second U-tube, started the siphon on both tubes, started up the pump and VOILA! it worked! later on last night, I took some water out of my sump since it wasn't quite flowing the way I wanted it to. After doing this, the second siphon tube kept sucking in bubbles until it completely stopped. The system is now running totally off of one siphon tube. I guess it was just a matter of getting the right amount of water in the sump. I kept trying to get the second tube restarted but it continued to do the same thing... suck in bubbles until it eventually stopped. Is it true that when you have more water in the sump, then the two siphon tubes would work? and when you have less water, you need less siphoning? I guess it makes sense to me, but maybe someone can clarify the science behind this a little more.

scubadude- I also saw the same thing as you... at one point when I had both siphon tubes in the overflow, I pulled one of the tubes out just to see if the other would act as a back-up and work on it's own. After the water in the sump looked like it was getting too low, the siphon must have gotten stronger and started pulling more water down and the water level in the sump went back up to normal. It was just a matter of waiting a couple more seconds and letting things catch up.

[Venaman]

thats EXACTLY what happen to me. .
i had all these air bubbles being sucked in from the u tube and never noticed, just thought it was a cheap overflow
so i bought another U tube dicovering i dont even need it

[bongobrian]

I guess it probably depends on the return pump that you have. I'm just guessing at this, but the stronger return pump you have, the more water you will need to be pulling from the overflow box (thus requiring more than one siphon tube and even a larger overflow.) I see things functioning as a loop. The stronger the return is, more water is being pumped into your tank, and more water is then being drained back down into the sump. Eventually though, with larger volumes of water (larger tanks) I think you would need more than one U-tube. Since my tank is only 46 gallons and sump about 13 gallons, a 600gph pump and a single U-tube do the job just fine. I always need to explain things in a way that makes sense to me. Maybe I'm totally wrong on this though. It's just what I have concluded from what I've seen so far.

[WannaBeAReefer]

Another way to think about it is this:

Water overflowed = water pumped by return pump.

This is true as long as the overflow and drain pipe can handle the capacity of the pump... i.e. the overflow can drain it faster than you can pump it.

If this is not the case then you will have problems... your don't drain fast enough and the main tank overflows...

It is not a good idea to adjust pump capacity to the overflow volume --rather you should oversize your overflow and just let the size of your return pump dictate your water volume.

[bongobrian]

I was thinking the same thing... and that's why I tried to increase the overflow volume by adding the second U-tube. Why is it that the second U-tube always eventually stops siphoning? is it because it is unnecessary and the system can run effeciently off of a single U-tube? Basically, my thought is that there has to be enough water being drawn into the overflow box so that two U-tubes are able to get a good supply of water flowing into them. If there isn't enough water being pulled into the overflow, then that would explain why one U-tube would stop. I know that increasing the amount of water in my sump will allow me to use two U-tubes. Isn't it true that the water level in tank will always stay the same? just the level in the sump will fluctuate.. correct?

[WannaBeAReefer]

The sump can be at any level as long as there is enough water to feed the return. i.e. you could have a 20g sump or a 100g sump feeding a 50g tank...

If your tank level is staying constant (mine for instance is about an inch over the overflow when the return is running) then you have reached "steady state" (return pump flow = drain flow) -- when this occurs are you running on 1 u-tube or 2?

[bongobrian]

I know the sump level can be any level... that's exactly what I was trying to say, I guess I didn't word it right. I was saying that the sump level can change, but the level of water in the tank will always be the same if you unplug the return pump, let the water drain down into the sump, and then start the pump again. When my system is in the "steady state" it is running off of just one U-tube. I can't get the second one to retain the siphon. The water level in my tank is also about an inch above the overflow teeth.

[mpopma]

I have a sump style refugium and I have been searching for a check valve that will work so that if/when the power goes out I don't have a giant mess from the tank siponing back into the refugium. I tried the local pet stores to no avail and then went to home depot and tried to find something there to fit the 5/8 inch tubing but unfortunately they just had check valves for sprinker systems that when pressure is applied they spray the water out (causing a giant mess). Just wondering if anyone had any suggestions/websites where I might find a check valve that will work for this purpose.
Thanks,
Micah