Originally Posted by
Cosmo
When I used to use 100% RO water I used commercial additives instead of natural (crushed coral) because it is easier to measure and get consistent results. I used Kent RO Right for Gh, Kent Ph Stable for Kh (NEVER add either of these directly to the tank!!), and Kent Discus Essentials for minerals etc. When I kept wilds I kept the Ph at 6.2, which, unfortunately did not allow me to get sufficient Kh and if I didn't do large daily water changes the water would crash within 24/36 hours. To stabilize the water would have required upping the TDS way into the hard water range, which would have at the same time raised the Ph. Best bet I found is to not use 100% RO water. At this point I do not use any at all but still add the Discus Essentials. If your tap water is unusable ( why?) they you need to up your RO production. Get hold of an Aquatec 8800, buy a second pressure vessel and two 150 gal membranes. If your source water pressure is sufficient you should be able to produce over 200gpd. All in all, however, unless you are talking breeding tanks aged tap water is your best bet - have you tried that and found it still unusable?