I change about 10% every two months,I add supplements at half the recomended dose, my readings are perfect and my tank is thrivimg.I know someone who might do a 5% water change every 3 months and his tank looks great! MGM,do what works for you,everybodys tank is not the same,once you find something that works for you,stick with it...

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"It's better to have a hen tomorrow then an egg today."

i got a 75 reef and a 180 fish only, i do RO/salt water changes when the mood hits me ,every 2 weeks ,3 weeks ,whenever i "feel" it needs it. can't hurt. 20 gals. on the 75 and 35 gal. on the 180 ,whenever,,,,,,,,,[img]/ubb/biggrin.gif[/img]