Missing a chromis this morning... He didn't come out for food and he wasn't around the normal hiding spots. I sure hope I don't have a predator in the tank.

Is it possible an emerald crab got him?

Maybe, but probably doubtful.

In my experience Chromis don't die, or if they do they rarely leave remains, just the mystery of their disappearance. Still though, I hope he shows his face later and was maybe just late getting out of bed.

I've had chromis that looked healthy and part of the community just disappear I have ever only found the remains of one fish the others who knows where they go.

On the other hand it could be hiding if you haven't seen it after 3 days most likely it has been consigned to the fish graveyard

Best case scenario is that the missing Chromis is a male and is guarding eggs. But I'm not incredibly hopeful of that, from what I understand their breeding in aquariums is relatively rare.

As soon as Golds gets their order in I will likely go pick up a few more anyway. They are so small and I like the way they school. Plus the "green" ones I bought are very blue.

Did a parameters check last night and the results look almost perfect. Do you ever have the feeling that things are going too well?

Ammonia: Undetectable
Nitrate: Undetectable
Nitrite: Undetectable
Phosphate: Undetectable
Calcium: 420
Alk: 8.3
pH: 8.18
Salinity: 52mS
Temperature: 81 degrees

Cleaning crew has almost all of the brown algae cleaned off the rocks; they are showing purple, white, and grey now for the most part. No algae blooms on my glass or equipment but I do get a little green growth here and there, which is handled by the cleaning crew almost as soon as I see them. No diatom blooms on my sand and the blue hermits are keeping it as tidy as an operating room. Coraline seems to be growing slowly but at a steady pace, and the feather dusters, corals etc. that hitch-hiked on my live rock seem to be thriving. Last night I had a turbo snail releasing his love juice into the water flow, little sucker was going at it for at least 20 minutes... The free with purchase rock crab I got is keeping my sump very tidy although I don't know how much he loves living in there. (No rock, algae, etc. for him to monkey with)

Doing a 20% water change this weekend, really just to replace trace minerals and bump my salinity slightly. I’ve been dosing with a coraline booster and adding calcium and alk using Seachem’s reef builder/buffer. I've validated all my test kits using their reference samples so I'm pretty sure my numbers are spot on.

worse thing about chromis is they almost always kill of the weaker of the bunch , schooling doesnt last long as pecking order is established:)

usually as they get larger:)

Plus one, I even had 3 established chromis from my buddies tank that was up for 2 years, it was a 90g. When I moved them into the 75 with less room there is only 1 left. Never had success keeping a bunch, but maybe in a bigger tank with more room they could be friends?

I had 4 blue green chromis in my 33 gallon for a year plus 5 more fish they all got along fabulously never no aggression issues but I also think its the way you introduce them to the tank as well everything was introduced at once cept the clowns. Same thing with my big tank I introduced all the fish from my small tank to the big tank at the same time as the fish I got from J&L and so far everyone gets along no aggression issues as of yet

theres always exceptions to the rules , its not a guarantee but what happens more times then not.

its not usually an issue with new fish but as they establish their territory and pecking order the weaker of the bunch will be knocked off, if they are all of even strength then it will take time for some to outgrow the others , if they pair off its even worse.

its not a guarantee but a general guideline with chromis:)

its possible , but more than likely survival of the fittest , however if a tank is large enough that one can hide and not be found then less chance of being killed.