How can I best protect my tank from overflows?

[JingoFresh]

So, I'm getting a pet octopus very very soon. After over a year of preparation and learning from here and TONMO, it is coming.

My tank has cycled and it is appropriately escape proofed, I can't wait.

My concern however, is how can I best prevent an overflow from happening?

This could happen from either the overflow box getting clogged and/or the siphon breaking, or from the return pump failing and the sump overflowing.

While I have the overflow fixed in place, the octopus may do something with the U-tube or perhaps block the overflow with it's body. This concerns me.

So, what are the best ways to

1) Stop the return pump if the siphon breaks
2) Maintain the siphon to prevent it breaking
3) Break the siphon if the return pump has a problem

How do most people here protect against overflows?

[jay.fishman]

Redundancy is the best solution. Have two overflows. Design the sump to hold all of the water that can drain from display tank. Use a float valve to cut return pump if levels are off.

[billdogg]

The very best thing you can do is get rid of the overflow box. U-tubes are notorious for losing their siphon. Research Durso, Herbie, and BeanAnimal drains.

[JammyBirch]

Design the sump to hold everything that the DT could drain, design you return chamber, if using a submersible pump, small enough to pump all of that volume to the DT and not overflow it, lastly add an emergency drain...a separate drain pipe that is slightly higher than your main drain..

[W1ngz]

Test, Test and test more.

Especially in light of your thread about electrical concerns. Recreate every problem you can think of from failed pumps, to power failures, lost syphons and blocked pipes.

[Indymann99]

the very best thing you can do is get rid of the overflow box. U-tubes are notorious for losing their siphon. Research durso, herbie, and beananimal drains.

+1

[CamDAX]

I have mine tank setup so that if the overflow siphon breaks the return pump will end up out of water and the DT can hold the extra water. Also if the pump stops working it's setup so the sump can hold all the extra water that the DT would drain.

+1 the idea of two non u-tube overflows.

[Waters40]

I am confused as to why so many people are afraid of HOB overflows. If they are set up correctly they work fine (I have used one for years without any issues). Although I have never lost my siphon, I have things in place in case it does happen. Same with the return pump failing.......a siphon hole (or two) protects you from overflowing your sump. As previous people stated, you just test both scenarios to make sure you are covered.

[thegrun]

In addition to the above posts if you have a controller or get one you can set a float swtich that will turn off your return pump if the water level in the DT gets too high.

[toothybugs]

Another vote for getting rid of the U-tubes. Mine was never a problem but I had to suck the bubble out every few days (this was before I found one with a powerhead attaachement).

Knowing what I know about octos I'd definitely rig at least a second overflow, fully capable of managing the flow on its own.

[JingoFresh]

I definitely can't get rid of the overflow and U-tube at the moment. It is something I will work towards but not for a few months, and I would like a short term measure in the interim.

Designing the sump to not overflow is not a problem...that just means adding a bit less water. Tested by turning off the return pump and verifying it doesn't overflow when it stops draining.

The problem is making it so the DT doesn't overflow. My overflow box is as low as it can go, but it doesn't take much to overflow it should the siphon break.

It sounds like all I need is a float valve switch to stop the return pump if the water in the DT gets to high, but I would not feel confident relying on this given the octopus may interfere with it.

Failing that, is there a way to restart the siphon if it breaks, or any other way I could turn off the pump to prevent it overflowing?

If an octopus covered my overflow to block water draining, the DT would certainly overflow.

[SGT_York]

+1 drill the tank.

[toothybugs]

The only other way to do this is to have a completely separate overflow apparatus that also goes directly to the sump, which will probably end up drawing bubbles in to the U tube in normal operation due to the low flow normally going through it.

[JingoFresh]

OK, So I need to go with the float switch to shut off the return pump in case of an emergency....what would be an example of one? I haven't found any.

The aqualift to ensure the siphon seems like it would just constantly be sucking water from the u-tube and back into the maintank....would it just be left on constantly?