Anti Syphon for sump. Ideas and My problem

[CraigyJr]

I drilled a hole in the top of the return tube to prevent a syphon in case of power failure. It works fine but the hole is not under the water level enough. It is picking up air and causing tiny bubbles and a burbing noise. My first question is, 1 what would be the best way to seal up that hole (epoxy?) and 2 whats the best method to prevent a syphon from occuring . Is the tiny hole okay, just needs to be lower. Whats your method???

 

[oranje]

Although I still haven't put one of these in my return tube, a check valve prevents backflow into the sump in case of dead pump/power failures. Basically, all it contains is a little trap-door type of thing in the valve, such that when water flows one way, it will remain open and life is good. If the water flows the other way, it swings back and seals up the tube - thus preventing backflow and a big ole mess.

These are available at Home Depot, as well as from various online retailers... check the plumbing section on
marinedepot.com.

 

[SPC]

CraigJr, are you talking about the return tube in a HOB overflow?
Steve

 

[reefland]

Although I still haven't put one of these in my return tube, a check valve prevents backflow into the sump in case of dead pump/power failures. Basically, all it contains is a little trap-door type of thing in the valve, such that when water flows one way, it will remain open and life is good. If the water flows the other way, it swings back and seals up the tube - thus preventing backflow and a big ole mess.
l]marinedepot.com[/url].

Check valves are known for failing in reef tanks. It doesn't take much growth in the pipe before it does not seal. Then you'll get the infamous "thunka-thunk-thunka-thunk" sound of the check valve failing (open/close open/close)

Fill the hole with epoxy or even some silcone might do it. Then drill the next hole correctly.

 

[CraigyJr]

I will do the epoxy, but i am concerned with the amount of time it will take to harden. I know it will harden in the water but will i have to shut the pump off for a while to allow it to harden. The pressure coming through the hole is pretty powerful.

Another thing. Can i drill the next hole in the tank or do i have to take the pipe out to drill. Jut worried about the noise and or pvc pieces floating in the tank

 

[reefland]

I would let the epoxy harden for at least an hour. I seem to remember that PVC shavings float. If so easy to remove. If not, no major issues.

It would be better to take the pipe out of the tank for drilling.

 

[flameangel1]

I do agree about the check valves !!
They ALWAYS fail at some point, due to bacterial "slime", bits of sand/coraline etc.

Drilled holes also fail, due to coraline,sea squirts etc.
If you use one, make sure to keep it open daily.
I, personally, keep the" return" just under the surface of the water, so it breaks siphon easily.
Therefore, no holes or checkvalves needed.

 

[reefland]

I have my siphon holes just about .5 inch under the water surface. Drilled at an upward angle. Provides nice surface agitation as well.

I would suggest you drill two holes, one on each side. Less likely that both would get covered.

 

[aquarist=broke]

CraigyJr,

I also did the hole drilling wrong. The hole I drilled was too high, so I placed a piece of airline tubing out of the hole along the top of the tank to the back of a top mounted powerhead. The tube hasn't plugged yet. Just a suggestion.....

 

[M.E.Milz]

I use both. The 1.5" return from my pump is connected to a manifold behind the tank near the top which splits the return into 8 separate 0.75" lines, each of which are connected to pvc returns spaced along the back of the tank.

I drilled a hole in each of 8 returns at the waterline, and a second hole about 1" below the waterline. I can't see how air would be draw into these to cause the bubbles (like a venturi) since water always seems to be coming out of these holes. Perhaps your source for the bubbles is someplace else?

In addition to the above, I added a 1/4" checkvalve to the top of the manifold. This serves as a backup should any of the drilled holes become clogged. It is also positioned at the highest point of the return system. I disagree that this checkvalve is bound to fail, or will become clogged. Unlike typical applications for using checkvalves, there is NO water actually running through the check valve. Thus, it should not get clogged with algae, saltcreep, etc. Nevertheless, that is why I also have the drilled holes.

PLEASE NOTE that this set-up has only been running for a short time, so I cannot vouch for its long term success. However, it does seem to work very well. When I shut down my pump (Dolphin 4500), and even though there is quite a bit of water in all of the return lines, the syphon is broken almost immedaitely and the water level in the sump only raises an 1" or so.

 

[M.E.Milz]

BTW, the 2-part plumber's epoxy will work just fine for closing up the hole.

 

[Dewman]

I agree with the 2-part epoxy. Get the stuff you use to attach your sps frags to live rock. Mine is pink and just looks like corraline algae.