Green Water - ARGH!

[AndyL]

Ok... I'm running out of ideas - can't seem to get rid of the plague.

For some odd reason, I had a green water outbreak ... 2 weeks ago (?). Figured same as with FW, water changes, adding some carbon/rowaphos/kent nitrate sponge resins would make it go away.

Well it hasn't - I've done 4 waterchanges each at 100% (Ok 97%, there would have been a bit of water left). Water clears for 12-18 hours, then turns bright green again. Adjusted the skimmer to be taking out 2-3L of skimmate per day (vile green stuff). Hasn't helped. 36 hours of darkness didn't help.

What's changed in the tank? Replaced old Iwasaki 10ks with some noname 14k's - 2-3 weeks before this started. added a sailfin tang and hawaiian cleaner - sailfin did pass on (but body was recovered). Hawaiian cleaner may be gone, haven't seen him of late - but the tanks rather hard to see in.

Is there any filter media that will filter this stuff out? Water changes are starting to get a bit expensive.

Luckily corals haven't been complaining too much some SPS had to move upwards, but are still showing good PE, LPS are just loving this...