One way valve for dosing pump?

[elliottsa]

About a month ago I purchased a Jebao dosing pump. I've been using it pretty much flawlessly to add a 2 part calc/alc to my tank. I have a JBJ 45 gallon all-in-one so the pump is in my cabinet with the 2 part solution bottles below the pump. The pump pumps upward to my tank.

Long story short - Today I check my bottles to see how much solution I have left and I have a pool of water in the bottom of my stand (luckily I had a plastic container there!) It looks like the lines were back siphoning the water out of the tank to the dosing bottles.

Do they make one-way-valves for dosing in situation like this? Thanks for any info. I'm new to dosing.

[SneekaPeek]

please look up airline tubing check valve, you'll find your solution there. However, they are not made for liquid solutions, so you might have to change them out periodically/ clean them.

edit: oh and make sure the lines aren't sticking in the water in your tank. have them hang a couple inches above the water line so that if it does back siphon, it only back siphons air. the solution should drip into the tank.

[AdamNC]

Cheaper way is to just raise the tubes about 1/2" above the water. It's what I've done with my ATO so as not to have any back siphon.

[elliottsa]

Thanks, Gents! Something so simple makes total sense now. Ugh... lesson learned!

[Gorgok]

A proper dosing pump should not be able to siphon one way or the other, one or more rollers should always be pinching the line. If it doesn't do that it will not dose accurately (or at all). I would see if there is an issue with the head itself or the line.

[slief]

A proper dosing pump should not be able to siphon one way or the other, one or more rollers should always be pinching the line. If it doesn't do that it will not dose accurately (or at all). I would see if there is an issue with the head itself or the line.

So true but it's a Jebao..Unfortunately, price comes before quality with them. At least the OP has an easy workaround. It certainly could have been much worse.

[Gorgok]

It could be something simple like the hose they decided to use has too thin walls so it doesn't pinch completely closed.

While siphoning tank water out is pretty bad, siphoning alk solution into the tank could be much worse. Not sure if the container is high enough to let that happen, it depends on where the line goes in the sump, but a simple check valve or raising the line out of the water will not fix it in that direction.

[SoloGarth]

Yup dosing pumps should not allow ANY water through in either direction when not running. Tube could be damaged or the wrong size. Something else could be wrong internally like the rollers being misaligned. You shouldn't need a check valve.

[zachts]

As others said raise the outlets above tank water level to keep tank water from back siphoning. Then check your line connections at the pump. If barb fittings are used make sure they are zip tied to insure they are sealed and not letting air in. If they still drain back to the bottles when the pump is off then you will not be able to dose anywhere near accurately enough. Inspect the pump heads and rollers and the tubing in the head. As others mentioned there is most likely a problem in the head. How many rollers? A decent cheap head should be using at least 3 rollers, 4 would be better, to ensure no siphoning. Tubing size could also be incorrect.

A quick check would be to disconnect the lines and try to blow gently thru the tubing while it's installed in the head, if you can blow air thru then the tubing is the wrong size for the pump head or it's just a cheap crappy head (which those are in my opinion). I which case even if you use check valves to stop the siphoning they will not dose accurately.

Check valves SHOULD NOT be needed for a doser as the rollers should be serving that function.