Do you only continually top off with RO water to keep the params the same or is the RO mixed with a small amount of remineralizer to add some minerals back? Even with pure RO top offs, won't you get a TDS creep eventually?
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.
Sump Pimp #2
My Tanks and my shrimps