Return Drilled or Over Top?

Bryce H. · 05/02/2018, 05:13 AM

I’m drilling my tank for my intake which is going to have 2 intakes as well as an emergency overflow. My question is on the return, should I drill it or just go over the top, with a siphon break, to prevent backflow in the event of a power outage? I’ve considered drilling and installing some type of check valve but have heard pros and cons.

homer1475 · 05/02/2018, 05:56 AM

I personally like the look of them being drilled in. Over the top looks rather ghetto to me. If your going through the trouble of drilling the tank for the overflows, whats 2 extra holes?

All you have to do is drill a small hole in the return lines somewhere near the water surface for a siphon break. Or place the returns near the surface so only a small amount of water drains back. Either way it's best to make sure your sump can handle any water that might go down there.

No one likes to suggest relying on check valves only because without routine maintenance they can and will fail. While they work just fine and some use them, use them with caution and design your system to not truly rely on them.

mcgyvr · 05/02/2018, 06:02 AM

^^ +1 to that.. Nothing more to add except don't just drill one siphon break hole just in case algae fills it or a snail sits on it at the wrong time (happened to me.. wasn't fun)

Dmorty217 · 05/02/2018, 08:17 AM

If you have a canopy to hide it, then over the top. If not I would drill it if you like the clean look

Darth_Tater · 05/02/2018, 11:47 AM

I vote drilled. Over the top makes putting a screen cover on the tank much more difficult and provides a path for tons and tons of salt creep!

You can't drill right at the top of the glass, but if you're worried about the sump flooding with an extra 90 degree PVC bend or two you can bring the return from the drilled hole to the water surface. Not the most elegant, but it's cheap and if you paint the PVC the same color as the back of the tank it's not too bad looking. With this method you also don't have to worry about siphon breaks.

ScottF83 · 05/02/2018, 12:44 PM

This is what I did. I drilled a good safe distance from the top and then realised the damn thing wouldn't break siphon even with a hole which would quickly get exposed as the level fell.

Solved by having a small upward arch in the tank side return piping created with two 45 degree elbows

So yes, definitely drilled but do think about that siphon

Quote:

Originally Posted by Darth_Tater

I vote drilled. Over the top makes putting a screen cover on the tank much more difficult and provides a path for tons and tons of salt creep!

You can't drill right at the top of the glass, but if you're worried about the sump flooding with an extra 90 degree PVC bend or two you can bring the return from the drilled hole to the water surface. Not the most elegant, but it's cheap and if you paint the PVC the same color as the back of the tank it's not too bad looking. With this method you also don't have to worry about siphon breaks.

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05/02/2018, 05:13 AM	#1
Bryce H. Registered Member Join Date: Apr 2018 Location: Northern Kentucky Posts: 26	Return Drilled or Over Top? I’m drilling my tank for my intake which is going to have 2 intakes as well as an emergency overflow. My question is on the return, should I drill it or just go over the top, with a siphon break, to prevent backflow in the event of a power outage? I’ve considered drilling and installing some type of check valve but have heard pros and cons.

05/02/2018, 05:56 AM	#2
homer1475 Registered Member Join Date: Mar 2015 Location: Upstate NY Posts: 5,313	I personally like the look of them being drilled in. Over the top looks rather ghetto to me. If your going through the trouble of drilling the tank for the overflows, whats 2 extra holes? All you have to do is drill a small hole in the return lines somewhere near the water surface for a siphon break. Or place the returns near the surface so only a small amount of water drains back. Either way it's best to make sure your sump can handle any water that might go down there. No one likes to suggest relying on check valves only because without routine maintenance they can and will fail. While they work just fine and some use them, use them with caution and design your system to not truly rely on them. __________________ 80G SCA Build: http://reefcentral.com/forums/showthread.php?t=2560256 Originally posted by der_wille_zur_macht: "He's just taking his lunch to work"

05/02/2018, 06:02 AM	#3
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	^^ +1 to that.. Nothing more to add except don't just drill one siphon break hole just in case algae fills it or a snail sits on it at the wrong time (happened to me.. wasn't fun) __________________ Who me?

05/02/2018, 08:17 AM	#4
Dmorty217 Saltwater Addict Join Date: Jan 2012 Location: Vandalia OHIO Posts: 11,624	If you have a canopy to hide it, then over the top. If not I would drill it if you like the clean look __________________ Fish are not disposable commodities, but a worthwhile investment that can be maintained and enjoyed for many years, providing one is willing to take the time to understand their requirements and needs Current Tank Info: 625g, 220g sump, RD3 230w, Vectra L1 on a closed loop, 3 MP60s, MP40. Several QTs

05/02/2018, 11:47 AM	#5
Darth_Tater Registered Member Join Date: Feb 2015 Location: Northern Utah Posts: 535	I vote drilled. Over the top makes putting a screen cover on the tank much more difficult and provides a path for tons and tons of salt creep! You can't drill right at the top of the glass, but if you're worried about the sump flooding with an extra 90 degree PVC bend or two you can bring the return from the drilled hole to the water surface. Not the most elegant, but it's cheap and if you paint the PVC the same color as the back of the tank it's not too bad looking. With this method you also don't have to worry about siphon breaks. __________________ It's probably in your best interest to ignore most of my advice.