Overflow box gurgling when return area of sump is low?

[vokrey09]

I have a 40B with a HOB Eshopps pf300 overflow, down to a small 10gal sump. The consistent water level in the sump is at 6", the return section (separated by two baffles) is about an inch lower than that and has a Jebao DC3000 return pump.

I've been having some issues dialing the return pump in to match the overflow (without triggering the float valve in the DT which shuts off the return pump as a failsafe). Even though I have a DC pump and a gate valve on my return plumbing (and a gate valve on the overflow!?, but that's a separate issue). Due to this issue I've unplugged my ATO (Tunze Osmolator) because when I'm not home and DT fills a little too much, the float triggers a shutoff and drains a portion of the DT water down to the sump, triggering the ATO alarm which no one appreciates haha.

While searching for a permanent solution to this (pls chime in on this if possible too) I've been topping off the sump by hand every day.

MY QUESTION I THIS.... why does my overflow box get low and make a gurgling noise when my return section of the sump drops due to evaporation!? I'm very new to all this stuff, but was under the impression that the display/overflow portion of the system should all be consistent and that any evaporation is only noticed in the return section of the sump..

PLEASE HELP EXPLAIN THIS TO ME, or maybe direct me to a solution

 

[arturoo1977]

My understanding its same as yours, evaporation should be notice in return pump section of sump. And gurgling noise of overflow should be due to a faster drain than return, so your gate valve on drain pipe should deal with that on a fix speed pump system or a mix between that valve and DC pump speed.
BTW, your pump speed is constant at level you set it? Cause if speed is fluctuating you will not be able to balance it.

 

[Reefpuck]

The lower the water level in the return section...the harder the pump has to work basically to pump water up to the tank. It's a small difference...but when you're trying to fine tune a drain line...it can make it an issue.

 

[Bryknicks]

You are correct in that the only water fluctuation should be in the return section of your sump. You're ATO should also be located in this section of the sump and not the display tank. Ideally the return pump is the only thing you should be touching to dial everything in. Any gate valves on the return and overflow should be wide open and just use the controller for the return pump to dial in the speed in which you want. I used to have the same set up with an Eshoppes overflow and Jebao pump and it worked flawlessly.

 

[DLHDesign]

The lower the water level in the return section...the harder the pump has to work basically to pump water up to the tank. It's a small difference...but when you're trying to fine tune a drain line...it can make it an issue.

Yup; this.
As the water in the return area decreases, the flow rate out of the pump decreases as well. This in turn causes the DT level to drop, which reduces the flow going into your overflow box. As that happens, the drains will start to siphon in air, which makes the loud gurgling noise - which also reduces the amount of flow out of the overflow box, which can further lower the level in your return section.

Getting it all dialed in takes a bit of fiddling. I favor the method of setting the pump to the flow you want, then dialing in the drains to match. Then I set up the ATO to maintain the level in the return area, with all sensors and alarms in that section.
Once it's all dialed in, I make sure to turn off the pump(s) and let everything drain out (including any gate valves that might exist) in order to ensure that I don't get an overflow.

Good luck and welcome to the hobby that we all love to be driven nuts by!

 

[Idoc]

I actually work mine opposite of @Bryknicks discussion above....I don't see any reason to apply back pressure on a DC pump with a gate valve when you can use the pump's controller to control the amount of flow. I think gate valves on return lines are best used to control AC pumps whose flow is a constant amount.

If you have a DC pump, set it at the flow you want and open the return line gate valve full open. Closing this return pump line only creates a backflow on your DC pump. A DC pump allows you to adjust the amount of flow by making changes on your pump's controller. Once you have the DC pumping at what you want to have returning to your tank. Then make changes to your return section...adjust the overflow drain pipe gate valve open or closed more in order to make that water level in your overflow go up to and just trickling over the emergency pipe. After you have this set...then look back at your return section of your sump...you should place a piece of tape or something on the outside of your sump to annotate the water level you want to maintain in your return section of the sump, which is typically 2-3 inches above the return pump's intake (but this can be anything really....you set it). Then, if the water is too low (below your tape mark), then you don't have enough water in your system and must add some more saltwater...if the water is to high (higher than your tape mark), then you have a couple options....either remove saltwater from the system until it is even with your tape mark, or open your drain line gate valve a little more at a time until the water drops to the tape line mark!

Pretty simple actually...once you understand the flow!

 

[vokrey09]

BUMP.. anyone else want to chime in on this issue? Still havent got this all figured out.

The hardest part of maintaining my tank has been getting this to work!

 

[Bryknicks]

I actually work mine opposite of @Bryknicks discussion above....I don't see any reason to apply back pressure on a DC pump with a gate valve when you can use the pump's controller to control the amount of flow. I think gate valves on return lines are best used to control AC pumps whose flow is a constant amount.

That's what I meant. The valves should be wide open and you use the pump controller to dictate the flow desired. @vokrey09 can you please give us more information and some pictures or videos showing the issues. That would be a great help in trying to solve your problem.

 

[Water Dog]

BUMP.. anyone else want to chime in on this issue? Still havent got this all figured out.

The hardest part of maintaining my tank has been getting this to work!

Do you have a prefilter sponge in your Eshopps HOB overflow box? If so, I‘m guessing that the sponge is clogging up and obstructing the drain plumbing. Thus, you‘re getting the exaggerated fluctuation in your return chamber even with the use of the ATO as well as the water level rise in the DT. Back when I ran an HOB overflow box this happened to me too. I ended up ditching the prefilter sponge and putting in a Stockman standpipe.

Ken Stockman's Standpipe Implementation - Durso Standpipes

Durso Standpipes are used to make your aquarium overflow (weir) nearly silent. We help you make your own or purchase them ready made!

www.dursostandpipes.com

 

[vokrey09]

Do you have a prefilter sponge in your Eshopps HOB overflow box? If so, I‘m guessing that the sponge is clogging up and obstructing the drain plumbing. Thus, you‘re getting the exaggerated fluctuation in your return chamber even with the use of the ATO as well as the water level rise in the DT. Back when I ran an HOB overflow box this happened to me too. I ended up ditching the prefilter sponge and putting in a Stockman standpipe.

Ken Stockman's Standpipe Implementation - Durso Standpipes

Durso Standpipes are used to make your aquarium overflow (weir) nearly silent. We help you make your own or purchase them ready made!

www.dursostandpipes.com

This makes a ton of sense. But the issue is I don’t have a predicted sponge! Could this happen as my in sump filter sock gets dirty?

see some of these pictures for my set up. As the ato fills the water creeps closer to the blue taped line, but eventually just drops back down and the overflow box shows the added water :/

 

[vokrey09]

That's what I meant. The valves should be wide open and you use the pump controller to dictate the flow desired. @vokrey09 can you please give us more information and some pictures or videos showing the issues. That would be a great help in trying to solve your problem.

Just posted some pics

 

[vokrey09]

So just to rehash... I opened the returns valve allllll the way. I turned the return pump to a level of flow I’m comfortable with. I adjusted to overflows gate valve to make the water level in the sump right at the blue tape line...
I tried removing some of the water from the sump as a test... and all it did was slowly lower the water level in the overflow box!? (I have no prefilter pad or filter sock on)

I really don’t know what could be happening here :/

 

[Water Dog]

Wait a minute... you have a gate valve on a single drain HOB overflow box set up? Open up that drain gate valve all the way and see what happens, disregarding the excess noise for the time being. Is the system and the water level in the return section able to self regulate now?

Single drain set ups, be it from HOB overflow boxes or Durso set ups should NEVER be restricted with a gate valve in any way.

 

[Bryknicks]

When you say the overflow box fills up, do you mean the box in the tank or behind the tank? I also used the stockman pipe in my eshoppes pf300 overflow and never had any issues like you are experiencing. As Water Dog said, make sure the gate valve on the drain is opened all the way as well.

Please post a picture of the over flow box on the outside of the tank for reference so I can see if anything sticks out as a problem.

 

[Water Dog]

I really think the underlying issue all along has been using the gate valve and restricting the flow on the single drain set up.

 

[vokrey09]

I've taken all of your comments into consideration and opened the return ball valve, opened the overflow gate valve ALL the way, which was making the backside of my overflow box gurgle very loudly. I made a standpipe from PVC and have quieted it down (although the overall sound from the tank is definitely louder due to the increased circulation into the sump.

The water line is at my marker in the sump, and the ATO is turned on, waiting to see if everything works now once evaporation occurs.

Thanks for all of your help up to this point!

 

[Bryknicks]

I've taken all of your comments into consideration and opened the return ball valve, opened the overflow gate valve ALL the way, which was making the backside of my overflow box gurgle very loudly. I made a standpipe from PVC and have quieted it down (although the overall sound from the tank is definitely louder due to the increased circulation into the sump.

The water line is at my marker in the sump, and the ATO is turned on, waiting to see if everything works now once evaporation occurs.

Thanks for all of your help up to this point!

The sump and/or overflow noise issue is a whole other issue. Lets get the tank running properly and then we can cross that bridge. When I switched to the stockman pipe it did make a world of a difference with noise but never silent.