Anti-Siphon for Returns

[jasonmrcdd]

Hey you silly reefing *******s!

Planning a new tank and wanted peoples opinions on the various ways to prevent your returns from reversing and sucking too much H20 into your sump in the even of a power fail.

From what I have seen, there are three ways I know of.

1) Drill a hole in the return line near the water line that will suck some air and break the siphon

2) Place return heads close enough to the top of the water level so that they only drain a little bit of water before sucking air and breaking the siphon.

3) Check Valves

I am currently using # 1 on my 46 and it works well and doesn't allow too much water ot be sucked into my sump (i only have a 10 gal sump so I don't have too much room for drainage). The thing I do not like is that the hole is just above the water line so it has a steady pee stream like flow of water. I am sure this diverts a little bit of my flow to the return, it makes a bit more noise, and makes more water splashing up and putting salt on the clear sheet protecting my lights.

I have seen people using # 2 effectivly, but I guess the downside is that your posistioning of the heads is a bit limited.

I have also seen check valves used and they seem that they are the easiest, and create the most flexibility, but how dependable are they. I have heard they are prone to failure.

Anyone have thoughts on this matter? Just trying to get some other opinions to help finalize the planning on my new system.

Thanks!

[Two Bit Scooter]

I've always done 1 and 2 with these things over the teeth of an overflow:

http://www.marinedepot.com/U_Tube_with_Directional_Return_Returns_Plumbing_Pa rts-Plumbing_Parts-FT0001-FIFTRP-4-vi.html

Make sure you drill the hole so that it doesn't spray up into your lights and be sure to have enough space in your sump for the displaced water.

[sdsocal]

I havent tried them yet but was looking into them for my current build for added protection.

Wye Check Valves are reliable and can be disassembled for easy cleaning to ensure they work when needed most. Check valves allow one directional water flow and are used to prevent back siphoning. They are commonly used on return pump outputs to prevent water overflowing the sump in the event of a power outage, pump failure or maintenance. Check valves should be the last line of defense against overflows for every tank

http://www.bulkreefsupply.com/store/1-5-george-fisher-wye-check-valve-swiss-made.html

[LarryM]

Design your system with a water level containment so it can handle without check valves. then you can install check valves so not as much water siphons out without fear should a valve fail..

[Two Bit Scooter]

Larry's a belt and suspenders kinda guy. :)

[jasonmrcdd]

Design your system with a water level containment so it can handle without check valves. then you can install check valves so not as much water siphons out without fear should a valve fail..

Thanks Larry. Can you clarify what you mean? Are you saying to use one of the other methods (1 or 2) and also put in check valves for convienence (but you have the other methods that are fail-safe anyways) (i.e. belt AND suspenders?)

Thanks

[Magiksurfman]

i think he means a combination of #2( Place return heads close enough to the top of the water level so that they only drain a little bit of water before sucking air and breaking the siphon.) and having a sump with enough "spare" room to accommodate the water that will drain when your returns reverse during a power fail.

then you can "put in check valves for convenience"

[patrickj4453]

Agree with Larry. Check valves are always good to have. But also leave enough room in your sump for backflow of water down your return. If you lose power to your return pump water will fill and possibly overflow your tank. Watch your tank and sump and test it. Fill the tank up and cut power to your return pump and see how much water drains down your return pipes into your sump. If 10 gallons of back flow water come down your return. Then leave about 15 gallons of empty space in your sump so you don't have to worry about it. Also mark your sump with a pen or small piece of tape to remind yourself where your desired water level is.

[jasonmrcdd]

i think he means a combination of #2( Place return heads close enough to the top of the water level so that they only drain a little bit of water before sucking air and breaking the siphon.) and having a sump with enough "spare" room to accommodate the water that will drain when your returns reverse during a power fail.

then you can "put in check valves for convenience"

Got it, thanks

And to clarify, I am currently using method # 1 on my current tank. The retrun will break it's siphon in the event of a power failure and the overflow will self start (once initially primed). My current sump has marks on the outside indicating the minimum and maximum fill levels so that I can quickly know if my water level is good. My current set-up is totally safe for an outage and I have the capacity for it in the sump. I mostly was looking for opinions if there was a better way of making the return siphon proof.

I think the consensus seems to be that placing the retrun vents high in the water, leaving enough room for them to drain completly if needed, and then using check valves so that the full amount doesnt drain every time I turn the return pump off (cleaning, etc) but, it COULD handle that amount fo water if the check valve fails...