!! damsel in distress

[i like fish]

so i have a yellow tail damsel in my tank, and i ahve a red hermit crab, fairly big, hes going back soon, but i jsut installed a new amiracle mud filter today, and it has a skimmer box and such,well everything was fine when i left for work at 330, when i got home, the damsel was/ is swimming erratically, so i checked him outand noticed all his fins looked all roughed up and they were fine when i left, i wonder is it possible the crab grabbed him, but let him go, or might it have been the skimmer box somehow, im confused, any ideas?

 

[scuba_steve]

the crab could catch him at night but dont see all the fins being shredded ! id expect to see a big wound of some sort! no other fish in the tank ? never used a mud filter but if no other fish are in the tank my guess would be water quality over anything ! they are hardy little guys ! i still have my first yellow tail from over 8 years ago and hes been to hell and back !!

 

[i like fish]

thats what i dont understand, hes been in there for a few days now, and perfectly healthy, and i figured the crab woulda ate him entirely if he got him, no other fish, the only thing it could be is the skimmer box, the water quality could affect a fish like that? i didnt think of that as being a means to shred the fins...

 

[scuba_steve]

yea if your water quailty is getting bad it will do all types of thing to a fish !

im lost on why ya think the skimmer box kinda lost there :-/

 

[scuba_steve]

remember a low ph is turning the water acidic