Is it okay to oversize my hang on overflow?

[JB33t]

I’m building a 25g SPS tank and I had a hang on overflow laying around however I know that it’s rating on the website is up to a “30g tank” I wasn’t able to find the gph rating anywhere they stopped making them. Anyways I think it will be too small since I want to be able to push more water with a bigger return pump of at least 500gph and I don’t think that overflow will be able to handle that. Therefore my question is if it’s fine to just be able to throw on an overflow thats rated much larger than my tank size will I run into any problems doing such? Thank you

 

[JB33t]

Also can anyone recommend a hang on overflow that would be large enough, as well as reliable. thank you very much.

that is unless I just get over my fear and drill the tank...

 

[Gtinnel]

I've never personally used them but Eshopps has a pretty good selection of different sizes. Also when sizing your overflow to the pump don't forget that the rating of the pump will be different than the actual flow rate of the pump due to head pressure.
I've only drilled one tank before but it is surprising easy to do, if I were you that is the way I would go. A hang on overflow scares me because if it looses siphon you'll flood the tank, unless you go with the CPR Aquatics one that has an aqualifter pump so it can't loose siphon.

Also, if you do decide to drill make sure the glass isn't tempered, if it is you can't drill it.

 

[ajm83]

Depends on the type, if it's the ones without a pump it is not okay to oversize it because you will get bubbles in the u-bend that don't clear and the syphon can fail to restart in that case.

 

[JB33t]

Got it, thanks yeah I’ve been watching some videos and I’m just going to drill it looks very simple. Just checked and my tank isn’t tempered good to go!

Depends on the type, if it's the ones without a pump it is not okay to oversize it because you will get bubbles in the u-bend that don't clear and the syphon can fail to restart in that case.

I've never personally used them but Eshopps has a pretty good selection of different sizes. Also when sizing your overflow to the pump don't forget that the rating of the pump will be different than the actual flow rate of the pump due to head pressure.
I've only drilled one tank before but it is surprising easy to do, if I were you that is the way I would go. A hang on overflow scares me because if it looses siphon you'll flood the tank, unless you go with the CPR Aquatics one that has an aqualifter pump so it can't loose siphon.

Also, if you do decide to drill make sure the glass isn't tempered, if it is you can't drill it.

 

[Gtinnel]

Got it, thanks yeah I’ve been watching some videos and I’m just going to drill it looks very simple. Just checked and my tank isn’t tempered good to go!

I've only drilled two holes in one tank so I am about as far away from an expert as you can get, but I think the key is plenty of water and not putting any pressure on the drill.
I also cut a piece of plywood with the same size hole so I could start the drill without it moving on me until I got a groove started.

 

[JB33t]

What size bulk head would you recommend 1/2”?

 

[JB33t]

I've only drilled two holes in one tank so I am about as far away from an expert as you can get, but I think the key is plenty of water and not putting any pressure on the drill.
I also cut a piece of plywood with the same size hole so I could start the drill without it moving on me until I got a groove started.

Did you pre drill a hole in the wood?