Overflow Box and Return Pump

[NervousReefer]

So I’m doing another wet test. I filled up the aquarium to the teeth of the overflow box (Eshopps Medium) and then the sump to about 2 inches from the top. I turned on the return pump, water started flowing thru the pipes but the water in the sump is still the same height as when I filled it and the water in the overflow box keeps rising and falling, making a gurgling noise every time.

What am I doing wrong? Thanks in advance.

 

[Silver14SS]

Do you have a ball or gate valve on the drain line? Sounds like the water may be draining faster than the return. Siphon starts and sucks the water down faster then starts pulling in air and gurgling.

 

[NervousReefer]

Yes. So closing it a little will help with this?

 

[Silver14SS]

It should, you want the main drain to be drawing water only without air to operate in a full siphon. If you have 2 drain lines, try to keep the water level in the box an inch or maybe more from going into the secondary drain.

 

[Billdogg]

What style is your overflow - i.e. Durso/Herbie/Bean? The problem and it's solution is somewhat different depending on what you have.

 

[NervousReefer]

What style is your overflow - i.e. Durso/Herbie/Bean? The problem and it's solution is somewhat different depending on what you have.

I have a Herbie. 1 main drain (1 inch) and emergency drain (1 inch).

 

[NervousReefer]

It should, you want the main drain to be drawing water only without air to operate in a full siphon. If you have 2 drain lines, try to keep the water level in the box an inch or maybe more from going into the secondary drain.

I tried what you said and it did stop the rising and falling in the overflow box but the sump water level is still the same height. I’ve watched several videos where after turning on the pump that section drops a little so you can mark your water level.

 

[NervousReefer]

Maybe my main drain is the problem. I have a strainer inserted in the bulkhead no pvc. Idk just guessing

 

[Silver14SS]

Take the strainer off for now, and try to get the water level in the box to stabilize halfway up the secondary drain line. It looks like there's barely any water in the box. The main drain should be submerged all the time so only water goes down it.

Edit to add pic. Here’s my overflow box. Ignore the middle pipe and pretend the closest one was just the bulkhead with no pipe like yours. All of the water is going down the main drain (closest), if something clogs it water in the box would rise to go down the emergency drain (open pipe).

 

[NervousReefer]

Take the strainer off for now, and try to get the water level in the box to stabilize halfway up the secondary drain line. It looks like there's barely any water in the box. The main drain should be submerged all the time so only water goes down it.

I turned the pump off so the water drain down a little. That’s why it looks low but my question is why isn’t the water in the return section going down? It’s still the height as when I filled it.

 

[lapin]

You are draining the overflow faster than the pump can pump it back into the tank.
Close the valve to the main drain a little at a time until water fill the overflow box to near the emergency drain level
It should fill up the box and just a trickle should go down the emergency when it is set correctly.
Then you should see the return pump section go down.

 

[NervousReefer]

You are draining the overflow faster than the pump can pump it back into the tank.

How do I fix this? I tuned the gate valve on my drain but still no luck in draining the water down in the sump.

 

[Silver14SS]

It takes a while for everything to stabilize. Adjust it as best as you can halfway up that secondary drain and leave it for 5-10 min. After that you can make fine adjustments, but again you want to wait several minutes after adjusting.

 

[NervousReefer]

It takes a while for everything to stabilize. Adjust it as best as you can halfway up that secondary drain and leave it for 5-10 min. After that you can make fine adjustments, but again you want to wait several minutes after adjusting.

Ok I give it a try. Thanks!

 

[NervousReefer]

It takes a while for everything to stabilize. Adjust it as best as you can halfway up that secondary drain and leave it for 5-10 min. After that you can make fine adjustments, but again you want to wait several minutes after adjusting.

One more question. Could my overflow box be too much for my tank? It’s an eshopps internal size Medium, rated for tanks up to 75g (800 gph). My tanks is only 50 gallons.

 

[Silver14SS]

Nope, that's why you have a valve on the drain

 

[NervousReefer]

Nope, that's why you have a valve on the drain

Ok! Thanks for all your help!!