Saturday, May 30, 2009


After my anemone moved I started to also see an increase in cyano bacteria growing on my live rock. I had just a little bit on my sand in a low flow area but not so much. For the first time had to start cleaning my live rock. During water changes I would just place the hose up against the rock and i would suck most of it up. Some cyano was also growing over one of my Palythoas plugs and they stopped opening. I had to carefully siphon the black cyano off the plugs during water changes.

I realized that my RO water wasn't getting purified enough. I measured a TDS level of 50 ppm. So I changed everything. New DI resin, new RO membrane and new carbon blocks and prefilter. Ironically my old RO membrane worked better than the new. The old one was some generic no-name brand 100 gpd. The new one is a Filmtec 75 gpd. I replaced the restrictor to the recommended flow rate and I'm getting a TDS level of 7 out of the membrane. Whereas in the generic one I would get 2 ppm. I thought it was bad because when starting the RO filter after it sat idle I would get a TDS level of about 200 ppm for a while before it would drop. Unfortunately, the new one does the exact same thing. So, I need to rely on the DI resin to knock the TDS level down to about 2 ppm. Unfortunately this exhausts the resin quickly.

Several water changes later the amount of cyano seems to be decreasing but is not completely gone yet.

When my anemone started moving around I wrapped my Koralia power heads with bridal veil netting so it wouldn't suck up the anemone. Now that it has settled in again and is no longer moving I removed the netting. I couldn't believe how much the flow in the tank picked up after the netting was removed. I bet the reduced flow was also responsible for the increase in cyano.