Plumbing question

[rael]

I purchased some used equipment and I have a plumbing question.

Given the below images:

The above images are my tank overflow and my sump. My question is, in this configuration, is there a chance the overflow would stop working (vacuum broken) and all the sump water would overflow my tank onto the floor? If so, what can be done to mitigate that possibility?

 

[bang guy]

With that configuration your sump will not overflow from the actual overflow.

However;

1 - if there is a power outage you need to ensure that the water cannot backflow through the return plumbing and drain the tank into the sump.

Anti siphon holes can resolve this but they need to be kept clean. An anti siphon valve can also work but I don't trust them in a saltwater system because of all the animals that can grow in the valve and prevent it from sealing completely.


2 - What can also happen is small bubbles collecting at the top of the overflow siphon. If this happens then over time they will collect and eventually slow the siphon to the point where the tank overflows and the sump goes dry.

This can be resolved by ensuring there is enough waterflow to carry bubbles all the way through the siphon. You should also check it once a week or so and remove any bubbles that have collected there.

 

[lmforbis]

I have a similar set up in one of my tanks and I have never had it lose the siphon since I set it up a year ago. I do check it regularly as Bang recommended.

 

[rael]

Ok, I thought the return valve was cracked but perhaps that hole is supposed to be there. Here is what it looks like:

Thanks for your help.

 

[bang guy]

Is the hole above the water line?

If not, how deep into the tank is it?

 

[rael]

Is the hole above the water line?

If not, how deep into the tank is it?

The valve hangs down about 2 inches into the water so the hold would be about an inch into the water.

 

[2quills]

Essentially 1" worth of water will back flow into the sump when the return pump is turned off.

What size is the display tank?

 

[bang guy]

You will need to test it by unplugging the return pump once you get everything going. Be ready to plug it back in if it looks like the sump is going to overflow.

1" deep sounds about 7/8ths too deep for my comfort but do the test. If the sump can handle the volume you're good to go.

 

[rael]

So essentially I should have the hole just a bit below the lowest point of the overflow intake, correct?

 

[bang guy]

My tank has an anti-siphon hole on the return slightly above the water and drilled at a down angle so that any water coming out the hole just goes straight into the tank.

I have built-in overflows though so it's a lot easier. Ask to see that others with external overflows do on their return line.

 

[rael]

My tank has an anti-siphon hole one the return slightly above the water and drilled at a down angle so that any water coming out the hole just goes straight into the tank.

I have built-in overflows though so it's a lot easier. Ask to see that others with external overflows do on their return line.

Yes, unfortunately the hole on mine points up so it would spray right onto the lights, so I guess I will position it just slightly below the water line (and perhaps make sure I have a little room in my sump).

Thanks everyone for the help.