Did you use tap water to start the tank? What about top offs? I see you wrote that you are now using RO
. Sounds good, but remember they are only as good as the membrane in the unit at the time. Depending on your financial situation, a TDS
meter might be in order. Personally, for a tank that size, I'd use distilled. If you have cyano
and lots of hair algae, then you have high phosphates. Doesn't matter what your test shows. Doubt that would kill anything though - that goes back to your water quality. Since you have some livestock, I'd remove them to a temp container, replace 100% of your water (rinsing any media with new SW
not the old stuff), and then after about 3-4 hours replace them. Be sure to feed very little over the next six weeks. This will give your friendly bacteria time to grow and allow you to be able to QT
any fish you might want to add. Good luck!