Calcium dispenser problem

[dmack]

I just purchased the Tunze Calcium Dispenser from Marine Depot. I keep finding my RODI water in my sump (where the dispenser is) has kalk in it. I think the check valve is faulty. Can you send me a new one? Or should I call Marine Depot?
Dan.

 

[rvitko]

The check valve is not suppposed to be what stops the back siphon on its own. If you look at all of the illustrations you will see that the line is zip tied above the 5074, if you don't do this the powder soon hardens the plastic in the check valve and destroys it. The check valve is just back up, if you zip tie the line as illustrated it will prevent this problem. A zip tie was included in the hardware package.

 

[dmack]

Thank you very much for your quick response!