sick fish

[border324]

hi guy and girls
it been a wile since i have been here i just moved. about 4 months ago.
i have a 55 gallon salt water tank with a wet dry filter big enough for it. i have 1-250 watt heater. and a mixijet 900 and 1200 for cir. i also have a protein skimmer that is not hooked up at the moment.
as for what in my tank?
i have 2 bag of agernite sand
55 pounds of select lalo live rock
and now 2 damsel fish and i have had about 12 snail and 1 crab.
i have let my tank run for about 4-5 months with just the snail and crab in it. ever thing was great till i put these damselfish in there along with with stress coat now with in 3 days my crab died and 1 damsel fish has been picking at the other. he always changes from blue to white and some times black. whats going on?

i think i got a parasite i am thinking about a uv lite to help out
what do you think?
thanks michael

 

[Nitrate]

I would recommend taking the damsels back to the store and leaving the tank fishless for 6 weeks. Then add something other than Damsels. They are mean little critters and chances are the aggressive one will eventually kill the other one. The color change may simply be the fish changing his color based on temperament. I never saw my damsels do that, but lots of fish can change their color to some extent. I have a porcupine puffer that turned almost totally black when I introduced a stars and stripes puffer to my tank and seconds later was back to normal color.

I don’t know of any parasites that the damsels could have introduced that would have killed the crab this quickly, but I'm by no means an expert on the subject.

Good luck, and HTH

 

[Hammer]

I agree with Nitrate loose the damsels, When I started my tank I used 4 damsels, outcome.....one killed the other/ the yellow one was so stressed it turned white then got pissed and nipped my star to death, and lastly thought hermit crabs were great fun when pulled out of their shells. In short I will never cycle or use damsels again, but thats just me

 

[border324]

thanks guys
i think i might take them back. as for a uv light what do you think about it good or bad ?

 

[Nitrate]

I don’t know much about UV except for what I was told at the LFS. I hope one of the guru’s chime in if this isn’t correct.

It's my understanding that the UV is only effective for a brief period in the life cycle of a parasite and its not a good idea to run one 24/7 so its ok to have in the event of an outbreak, but it shouldn’t be used to prevent one.

I borrowed one a few months ago when I thought I was having an outbreak, but only used it for a week or so. I never had the outbreak I feared was coming so I don’t know if it prevented it from getting bad or I was just being paranoid to start with.