Originally Posted by flanque
Hmmm... cos I have a hermit crab, corilamorphs and some button pollups (see this link
) and they all seem fine.
That's because all mentioned do ok at 1.019 sg
. If you had lowered it to 1.009 then it would have killed them off.
As mike said it's best to QT all your fish and reduce sg
to 1.009 for 6 weeks and slowly increase back to normal sg
levels topping off with well mixed SW
to increase sg
Fish have little trouble adjusting to quickly lowering sg
levels but it can adversely affect mobile inverts/corals. Luckily you didn't lower too much but you also did little to eradicate your whitespot problem.
If you do QT all your fish and drop the sg
to 1.009 I'd use a refractometer for accurate sg