Tap water and Prime for initial fill

[AZDesertRat]

Incorrect. There is no MCL for TDS, look it up. Since it is not a measurement of anything specific and not a health risk there is only a number pulled out of who knows where as a "guideline". It means nothing and is not enforceable. I should know, I have operated public water systems for 40 years.

 

[Sabellafella]

I ran my hose up the side of my house threw my window into my rodi unit acually handled head pressure verywell but took about 2 days for 120 gallon well worth it, if you use tap phosphate will seep into your dry rock and causr problems for you for about a about 2 months

 

[Sabellafella]

Unless you want to exhaust a pound of gfo dont do it , trust me i didnt wanna wait either and in staten island or brooklyn tds is only 40 45 and still had problems with phos on my first 2 tank because of initial fill

 

[Virtualbasil]

You are rolling the dice if you have no idea what's in your water. RODI all the way