check valve question

[scarface70706]

can you just use any old check valve from your local HD or lowes? i know there are some metals that dont mix right in SW and i see theres some metal in the check valves. are these check valves ok to use or is there some other product i should be looking at for my system. thank you in advance.

[OhYeah]

I would like to know this also.

[slief]

I would avoid check valves at all costs. I have had them fail before and it was not pretty! It's not if, it's when they are going to fail. That said, if you have to use a check valve you want one that is clear so you can see into it and rebuildable (like this one) so you can swap the parts when they get coated before they fail. Be prepared to change the parts every 6 months if not more to be on the safe side. Like I said though, they WILL fail you! We have too much calcium and other stuff that coats and or grows on the insides of them to be reliable for any length of time. Beware!

[Mouse]

+1 Its not if they will fail, but When they will

[Rockhead21564]

+1 on the WHEN! But if you do use them, don't use the ones from Home Depot or Lowes. They are a spring loaded type, you would need to use the flapper style. The springs in the spring load type rust and can cause the spring to stick at a angle. Where did you want to put a check? Good luck

[TheFishMan65]

+1000 avoid them if you can

[scarface70706]

i have one on my mag 9.5 return. i was always told to have a check valve. i have a back up just in case something will go wrong. i know things break and fail but a little insurance is ok IMO. but what im worried about is what does the salt water do to the metal inside. i do have the one with a spring inside and have seen the check valves on SW websites which i will get one day. but im just wondering if the combination of salt water and metal create some kind of foul element in my water that will harm my fishes and corals.
ps: thanks for the responses guys.

[kaipo13]

I found this and I was thinking of installing 2 on dual return pumps

http://www.plasticvalves.com/ball_check_valve.html

I wouldn't use metal

[krshlln300]

if anything you may have some heavy metal issues with iron possibly but the check valves from marine depot are relatively cheap, also you may want to consider just using an antisiphon hole in your return, (in-tank side of course) maybe at the top of the return in the loc line, all you need a very small pinprick type hole (mine is around 1/16) of an inch which allows for a minimal amount of water to be sucked back through the pump before the siphon is broken, this method very rarely fails as long as the water flow isn't interrupted for very long (more than a few days) at one time, and is pretty much free unless you don't have access to a drill and small bit.

[tkeracer619]

I have seen them fail not only by not stopping back flow but actually bursting in half and causing a major flood.

Do not rely on or use check valves.

[OhYeah]

Originally Posted by kaipo13

I found this and I was thinking of installing 2 on dual return pumps

http://www.plasticvalves.com/ball_check_valve.html

I wouldn't use metal

I like this because it does not have metal but from reading the other post, calcium deposit may cause the ball to get stuck and may not function properly.

[sbeason]

+1 on slief. I have used this exact type of sing check without any problems for years. The good thing is, since it is clear, you can see the inner workings of it. Simple to replace as well if it ever goes bad since it is double union.

-Steve

[TheFishMan65]

Originally Posted by tkeracer619

I have seen them fail not only by not stopping back flow but actually bursting in half and causing a major flood.

Do not rely on or use check valves.

I think any of the plumbing that has two pieces glues is at risk. I had the PVC to brass adapter on a shower split one me. I wish it has just been something under the tank.

Anyone know of a good way to inspect parts?

[scarface70706]

yea im mostly worried about heavy metal poisoning for my coral and fish. how much harm would this do to the livestock? i do like the plastic check valve mentioned and will most likely change my spring loaded one with the non metallic check. i do have a siphon break on my return line at the bottom of the elbow in the middle of the 90 degree. it came like this from aqueon or what ever company that sells the overflow kit with the telescoping inlet which seams pretty standard for all reef ready tanks. it was about $50. idk if that will ring any bells for you guys to get a general idea of what i have.