RODI Filter ???

[jerryc]

My first water that i get from my 3 gallon tank will read high.
But after that the water i get as a slow stream is at o has
anyone else noticed this

 

[AZDesertRat]

That is normal. Pressure tanks collect what is called "TDS Creep" water. When membranes sit idle the water inside tends to pass more freely from the dirty to the clean side of the membrane, this is osmosis. That high TDS water comes out the good or treated water line until the membrane clears itself and starts making good water.
If you have a large storage vessel the effects are diluted or reduced but in a 3 gallon tank it keeps collecting and getting worse until it is flushed out.
It is not recommended to store RO/DI in a pressure tank for this reason, or to even store RO in a small presure tank if you intend to later pass it through a DI filter since it will wear the DI out much quicker.
One solution is store RO/DI in a brute trashcan or other storage vessel so you can produce water in long uninterrupted runs so the TDS stabilizes. Another is a much larger pressure tank that does not cycle on and off as often, I once used a 14 gallon pressure tank that allowed larger pressure drops before the RO kicked on again.
In the meantime just make sure to completely empty the presure tank at least every 7-10 days and allow it to refill with fresh water.

 

[jerryc]

Thanks' i just hadn't noticed it before. Thank ill set up a trash can and do away with
the Pressure tank.