sailfin tang goen crazy........

[adjr221]

I have started my 150g tank two month ago. Started out by two damsels and kept them for a month. Last week I added two clowns, and they been doing good. Today I got a powder blue tang, and sailfin tang. The powder blue doing good so far, but the sailfin tang went crazy when the lights were tuned off. It started jumping up and down like mad and then laid down on the sand like she died. And when I turned the light back on she started swing around for a little bit and then settled down again….. so I took it out and it seems like ding now……..

What has just happened???????????
Water conditions are good nitrate, nitrite, ammonia are zero. pH 8.2, specific gravity 1.022, temp 80…

 

[TCTFish]

Sudden darkness and sudden light can scare fish. some have fatally injured themselves going crazy like that. The best thing for this is to have separate switches for daylights and actinics. Turn the actinics on about half an hour prior to the daylights, then at night, turn off the daylights about half an hour prior to the actinics. It allows a dusk and dawn period to ease the fish into day and night.