power loss and siphoning

[tortfeasor]

I recently bought a 90g predrilled reef ready glass tank. I've had experience in the past with hang on overflow boxes but am running into design issues and need help. My tank has a partitioned section on the back of the tank running its entire height. Its designed so that water enters the partitioned section through holes cut into it up and down its entire height. The drain and return holes are on the bottom of the tank rather than on the backside, whereby the plumbing then runs through the stand and into the sump.

I'm currently designing the sump and associated plumbing.

The issue I'm having is with potential power loss. I've read a lot about people cutting holes in the return line to break the siphon in the event of a power loss, but it occurs to me that with the tank's design and having holes for water entry up and down the entirety of the overflow section, how do I prevent a continuous flow in the event of an outage?

The only solution that I can think of is to run a pipe vertically from the bulkhead on the drain side and have it rise all the way to 1" or so from the top of the water level so that if an outage occurs, the main tank will drain only to the top of the drain pipe. Then I just need to make sure there is adequate room in the sump to allow for the increased volume without flooding. Is this a good design or is there a better way to do this? If I do it this way, do I still need to drill a sipon break on the return side as well?

Thanks in advance.

 

[wildman926]

Its designed so that water enters the partitioned section through holes cut into it up and down its entire height.

it occurs to me that with the tank's design and having holes for water entry up and down the entirety of the overflow section, how do I prevent a continuous flow in the event of an outage?

You are correct, that your tank will drain entirely in the event of a power outage. Replace the overflow with a standard unit, and be done with it. Not a hard task to do if the current one is attached via silicone.

 

[fishgate]

Does the overflow section have a double wall? My Aqueon overflows have double walls with drain slots on the top middle and bottom. However, just the outer wall has slots so water only flows into the overflow from the very top of the inner wall. This prevents excessive drainage in the event of a power outage. The holes in the overflow are also on the bottom of the tank. Both the drain and the return should have plumbing that brings it up close to the top of the tank.

 

[username in use]

^^^ what he said

 

[tortfeasor]

yeah it has a double wall. I guess I'm still just wrapping my head around it. I think I may just buy the overflow kit rather than making a DIY. Cant really think of any real advantage to making one on my own and for $50 it doesn't really make a lot of sense to save 25 dollars and risk flooding the house if I don't have all the kinks worked out.