of course obet, but still a loooooot cheaper than running a UV, where a lot of other reefers in other fora, say does nothing to rid of ich. isa pa, pwede naman nyang bawasan muna tubig ng tank nya kung di naman sobrang dami ng fish e. of course (again), the month or more time includes the gradual re-alignment of his salinity back to its old level, thus, he really needs to read about the proper procedure. anyway, it's his call, i just gave him my thought on his problem since he is soliciting advice in a forum.