Check Valve Confusion

[shrimply]

OK, so anyone who's read my journal ( not sure if that includes anyone) will know that I received a broken check valve from aquatic magic, I'm hoping they are going to send out a replacement but ain't holding my breath.

So I've been doing some researching, firstly it seems almost impossible to buy glass check valves individually on ebay and the only other place i can find them near affordable is Aqua Essentials and paying £3.99 seems Ok but if you add the shipping its a bit ridicules. So any suggestions are welcome.

OK, the question is in Aaron's guide he uses two check valves. On before the bubble counter and one after. Now the one before I can almost understand ( back to that in a second) but why do you need the one after, in the unlikely event that water is sucked out the tank, I am not the least bit worried about the back flow of water going into the bubble counter, its got water in it anyway, as long as it doesn't enter the solenoid and regulator I'm not too worried.


Now the one before the bubble counter is also a mystery as the bubble counter holds water which does not go back down the tube, at least with the one I've bought. Picture below. Now I'm not totally sure if I'm correct in my understanding that no water should run out of the bubble counter, but that seems to be the case.

So if the bubble counter won't let any water through it then isn't it the only thing you need in the way of a check valve?

I'm sure you'll point out how completely stupid I'm being but nevermind.

 

[aaronnorth]

I dont know why i put 2 check valves in, i only use one probably a mistake on my behalf unless someone gave a valid reason that i have forgot about

I shall edit the guide, sorry for the confusion,


The reason water doesnt go back through the BC is because of the pressure already in the airline. The water cant go down because it is being blocked, but in the off chance it may siphon into the reg, a check valve is a cheap but valuable inevstment.
A plastic check valve is fine but they are prone to leaking, i used one temporaarily and superglued the joints to help.

 

[shrimply]

Yes, thinking about it that makes perfect sense, and is fairly obvious really

Definitely fit one before the bubble counter although it will probably be a plastic one initially, cheers.

 

[shrimply]

lol, just thought I'd update I answered my own question, I imagine it depends on the bubble counter but with mine you need the check valve above it so that there is an airlock thing when the systems off, like you holding your finger over it. Otherwise the water runs down into the check valve behind the bubble counter