Safeguarding an HOB Overflow Box

[BTB0923]

When I started my 55 gallon reeftank I got an Eshopps HOB Overflow box that worked great, but always had me worried. There is always the fear that you will lose power, the siphon will be broken, and then when the power resumes your tank will overflow because the overflow siphon is no longer sucking the water into the sump.

A common safeguard for this is to get an aqualifter that sucks air out of the top of the overflow tubes. This works because in the event that the siphon is broken the aqualifter will suck water back up into the tubes and restart the siphon when the power comes back on.

I have been using this method for a while, but I noticed that over time the airline tubing inside the overflow tubes would slide down the back of the tube making the whole aqualifter setup useless until the airline tubes were repositioned. Repositioning the airline tubing inside the overflow tubes and getting them to stay in the right spot is a HUGE pain in the ass, so I decided to make a more permanent fixture with some airline tubing valves and silicone. Seems to be working great so far....

 

[CHOMPERS]

When I was using that type of overflow, I had the same thoughts but with installing a check valve instead of the needle valves.

Since you are losing syphon at powering down, that hints that you aren't using a stand pipe(s) in the overflow. Try one in each bulkhead and you'll wonder how you made it this long without them. Make them to extend to just under the level of the bottom of the teeth of the tank side box.

 

[BTB0923]

Since you are losing syphon at powering down, that hints that you aren't using a stand pipe(s) in the overflow. Try one in each bulkhead and you'll wonder how you made it this long without them. Make them to extend to just under the level of the bottom of the teeth of the tank side box.

I'm not losing siphon at powering down, the ends of the tubes are well below the water level in the tank and the overflow. The overflow box was designed not to need stand pipes. Its sectioned into two halves and when the pump is turned off the half with the pipes in it holds enough water to maintain the siphon. I made this adjustment as a back up just in case something wierd happens. Thanks for the advice though!

Also, I'm not sure but it seems like you might be thinking the aqualifter is sucking water up out of the overflow and into the tubes...its actually the opposite. In the event that the siphon is broken, it pulls the air out of the tubes and water from the overflow gets sucked up filling them up and starting the siphon again.

 

[xdragonxb0i]

sorry to revive. would u like to make a DIY for this

i need to do the same thing. I just dont understand it completely how it works

 

[bitteraspects]

its pretty self explanatory.
drill small hoiles in the U tubes.
install a inline check valve (one way valve flowing out of the U tube)
seal around the check valve with silicon
connect airline tubing to the check valves
connect airline to an "aqualifter" (the white air pump looking thing in the pic)