FS Tunze Osmolator and solenoid valve

[bhazard1]

Originally Posted by abcha0s@conceptaquatics

Since it's sold, I don't mind pointing out that using the solenoid hooked directly to an RO/DI unit is a great way to destroy your RO membrane and will cost a fortune in DI resin. RO membranes are not meant to be used in this way.

For the buyer, it would be a much better idea to fill an RO resevoir that feeds into the tank via gravity. The solenoid would control the flow from the resevoir to the tank, but the RO unit would not be part of the constant on/off. Perhaps that's what your planning.

For optimal performance, an RO unit should always be allowed to run long enough for the TDS to reach the lowest value that the membrane is capable of producing. Ideally, the membrane should be flushed at the start of every duty cycle.

A good deal on parts though. No worries there.

- Brad

Not sure I agree. I haven't been burning through my RO membranes. If I get a glass of water from the fridge which is hooked up to the same system and pressure tank, that is probably less water than my tank gets when topping off. As far as DI resin goes, mine lasts for quite a while and if I do things as you suggest above I might save $10 per year in resin? To me the convenience is worth it even if it cost me an extra $100 per year in membrane and resin to do it with a solenoid.

[justincgdick]

Originally Posted by bhazard1

Not sure I agree. I haven't been burning through my RO membranes. If I get a glass of water from the fridge which is hooked up to the same system and pressure tank, that is probably less water than my tank gets when topping off. As far as DI resin goes, mine lasts for quite a while and if I do things as you suggest above I might save $10 per year in resin? To me the convenience is worth it even if it cost me an extra $100 per year in membrane and resin to do it with a solenoid.

Have you been testing the water regularly to see if it has still been working as effectively as it should? Everything I've researched has people saying that the membranes wear out faster.

[bhazard1]

I constantly monitor with a tds meter plumbed in on both sides of the DI resin. I'm sure it probably does wear out the membrane a little quicker. I guess the question is whether the convenience is worth it for a little bit of added expense.