internal overflow issue

[jvilla58]

Ok everyone I have a bit of a dilemma. The tank I have has an internal overflow but the wall has a hole about 4 inches below the teeth for the return. I want to be able to put the hole in the pipe to prevent a siphon.
My question is do i leave the return in the hole and drill into the pipe or run the pipe over the wall in order to put the hole? sorry if this is confusing.

 

[seventhz]

If it were me, I would either go over the top of the wall or put a check valve on your return in case of power failure. The check valve would most likely reduce flow rate though. I have just a small portion of my returns out of the DT water (~1/4") so that they draw air, preventing a siphon from starting, in the event that the pump stops.

 

[uncleof6]

Ok everyone I have a bit of a dilemma. The tank I have has an internal overflow but the wall has a hole about 4 inches below the teeth for the return. I want to be able to put the hole in the pipe to prevent a siphon.
My question is do i leave the return in the hole and drill into the pipe or run the pipe over the wall in order to put the hole? sorry if this is confusing.

Why? That hole would do very little for you, if something got stuck in it, even as minute as a flake of coralline.

For one, if the return is 4" below the teeth, that return is way too low, and it needs to be raised till the return is within 1" of the water surface. At that point, with simple calculations, you can determine how much water will "drain down" in a power out, and cofigure your sump to accomodate that drain down. If it can't, then you need a bigger sump, or it needs to be reconfigured so it can.

Anti siphon holes just the same as check valves, are not failsafes to prevent your sump from overfilling. The only reliable failsafe is plenty of sump volume. One of the biggest violations of this, is running the sump more than ~half full "to get more water volume," or to have a bigger "fuge." Both notions are a bit "not well thought out."

I don't know your particular setup, however, most folks overly concerned with power out drain down, are violating that principle, because their baffles are too high, or have a fuge in a 10 gallon tank, a 10 gallon fuge in a 20 gallon tank, etc.

 

[jvilla58]

Why? That hole would do very little for you, if something got stuck in it, even as minute as a flake of coralline.

For one, if the return is 4" below the teeth, that return is way too low, and it needs to be raised till the return is within 1" of the water surface. At that point, with simple calculations, you can determine how much water will "drain down" in a power out, and cofigure your sump to accomodate that drain down. If it can't, then you need a bigger sump, or it needs to be reconfigured so it can.

Anti siphon holes just the same as check valves, are not failsafes to prevent your sump from overfilling. The only reliable failsafe is plenty of sump volume. One of the biggest violations of this, is running the sump more than ~half full "to get more water volume," or to have a bigger "fuge." Both notions are a bit "not well thought out."

I don't know your particular setup, however, most folks overly concerned with power out drain down, are violating that principle, because their baffles are too high, or have a fuge in a 10 gallon tank, a 10 gallon fuge in a 20 gallon tank, etc.

I get what you are saying and it makes total sense, but I just the the little safety it adds. But I will be sure to keep what you said in mind.
So I will move the return, what is the best way to cover up the hole in the overflow wall?

 

[uncleof6]

Leave it, it is not hurting anything at all.

 

[leveldrummer]

Leave it, it is not hurting anything at all.

i disagree. depending on how deep the drain is inside the overflow, this can cause the tank to drain much more water before running below the drain line. with the hole plugged, the tank will drain down to the top of the overflow, then only the overflow will drain till its below the drain pipe.

To plug the hole, you can weld or silicone a peice of acrylic/glass over the hole on the inside. match what ever material the overflow is made of and attach it accordingly with the appropriate glue.

 

[uncleof6]

i disagree. depending on how deep the drain is inside the overflow, this can cause the tank to drain much more water before running below the drain line. with the hole plugged, the tank will drain down to the top of the overflow, then only the overflow will drain till its below the drain pipe.

To plug the hole, you can weld or silicone a peice of acrylic/glass over the hole on the inside. match what ever material the overflow is made of and attach it accordingly with the appropriate glue.

Good point. I will ammend to "depends"