Likely causes?

[cbass488]

I've had a pretty good cyano outbreak and decided that this past weekend when we were away camping was a good time to follow the directions in the stickied cyano thread above. I scooped out the top layer of cyano covered sand, did 2 good 30% water changes and sucked out all the cyano I could see, and then I wrapped the aquarium in cardboard and kept it lights out for 3days.

The problem is, when I removed the cardboard and turned the lights back on, I was missing 2 fish. My yellow watchman and my royal gramma have not been seen in the 3 days since turning the lights back on.

I'd like to replace them, but want to try to investigate the reason they went missing 1st so I don't repeat.

Other known inhabitants of the tank are 1 tank bred ocelaris, 1 banggai cardinal and 1 six line wrasse. Several turbo, cerith and astria snails. The royal gramma was a new resident, and he had been picked on by the wrasse for his 1st couple days. They then spent about 3 or 4 days co-existing and pretty much ignoring each other, they could occupy close space and not seem to even notice each other.

Had the skimmer running good, and water perameters are good.

I did see a new 'cave' burrowed under the live rock and none of my fish (to my knowledge) were burrowers, so I assumed it might be the cereth snails.

I checked my overflow and the floor around the tank and had no luck finding anybody.

Equipment includes Remora Pro S hob skimmer with surface skimming box, fluval 306 canister, aquaclear 70 converted into a fuge and a fluval sea circulation pump. Lights were out. 55 gallon tank.

Corals include a big frog spawn, a flowerpot, a fox coral, a paly, 2 candy canes and some zoos.

Any suggestions as to possible senarios?

[Reefmedic79]

They could still be possibly hiding, I've had fish disappear for a couple weeks, only to be found when I least expect it. The watchman could have dug the hole and be living in it.

[Sugar Magnolia]

Just wait it out. The watchman is likely under the rocks as they dig burrows. Grammas tend to be shy so it may just be hiding in the rockwork.

[devimik]

Yep, agree with the above comments. My Yellow watchman disappears for days on end even with a normal light schedule. That is normal for them. My Royal Gamma has many holes and hiding places in the rockwork and hides a lot of the time. I can see if yours was in darkness for days, he could still be hiding. I'd give it some time before trying to replace them.

[cbass488]

Sounds good, thanks guys! It just isn't like either fish, they both had their regular habbits (though the gramma only had 'em for a week lol)