Any aquarists on that can help me solve a dilema?

How difficult would it be to scoop up the other fish in the tank? Scoop them up and put them in a temporary holding tank while you deal with the target fish. When he’s isolated you can either starve him (?) into a live trap (if your intent is just to put him into another tank, sell him, etc.) ... or whatever else you have in mind.

@CyanoticWasp yeah it would be very difficult to scoop up the other fish sadly…I have about 140lbs of live rock in the tank with many caves and nooks and crannies for all the fish to dart into is the problem. “I’ve tried leaving the net in the tank for a few hours so they would get used to it and then lure him in with some food, but he knows as soon as I raise up the net and takes off behind all the rock work. If I remove all the rock that has been established in the tank for a year and a half it will unsettle the sand which can cause water chemistry problems and could possible “nuke” my tank. This problem fish though will hardly let any others eat and will kill anything new I put in the tank. Peakock Flounder was $40, he killed it the same day I put it in the tank. Might as well have just flushed the money down the toilet. Not to mention the poor flounder.

I was thinking of trying to fish him out the classic way, bait and hook. I’m wondering though if they make a hook small enough for a 3 inch fish.

this is what he looks like
http://www.tropicalfish.at/saltwater/damselfish/damselfishSergeantMajor2.jpg

Do you have an auxiliary tank for your rock? You may have to do this over time, removing just a few pieces of live rock to a good tank until you have removed the obstructions, then catch the fish and slowly rebuild your reef. It could take weeks, but you’ll get rid of the fish without destabilizing your main tank too much.

@dpworkin I have another tank but its just a 10 gallon holding/hospital tank. My rock won’t even fit in there sadly.

Oh, that’s really too bad. But a tank alone isn’t too expensive, and maybe you can run it so that your current filters and skimmers treat the water in both tanks temporarily, to keep the rock healthy.

@dpworkin Yeah I could buy maybe a 30 gallon tank to hold it, I was reading something that said I could store the water in some buckets and drain it almost to empty, the corals would be safe, it said they would just think it’s something like a “low tide” and the fish in question would swim to wherever the most of the water is, so I could dig a pit in the sand so this pit would hole most of the water. It would be a very short low tide sensation. Sounds feasible or not?

I was hoping you could do it in the least disruptive manner, but if you have the guts to try it, it sounds good theoretically. The problem, as you know, is the stuff that happens when you stir up the substrate. If it were my tank, I think I might try to avoid that if I could.

I should say that I had my marine tanks in the very bad old days (early 1970’s) when you needed a team of people working 24 hours to keep a tank balanced. I understand things have improved quite a bit, so my advice might be old-fashioned and pessimistic.

Yeha sounds a bit weary for me to drain the tank, I might just try the moving the rock and getting it out of theere or at lleast some of them.

oh and if anyone wants to my tank here it is or at least a section of it.

http://img685.imageshack.us/img685/6459/55g.jpg

as you can see this problem can pose a HUGE headache grrrr

What a beauty, though! You should be proud.

@dpworkin thank you, and thanks for the advice also!

I would talk to @uberbatman who is the resident expert at all things aquarium.

@SeventhSense I sent him the question about a minute after this was posted.

Dude that definitely sucks. Damsels are complete asshole fish. Let me guess, someone said you should cycle your tank with them and you’ve been stuck with the fucker since?

Anyway, I have one trick that has worked surprisingly well for me. Get a soda bottle and cut the bottle at the top, invert it and glue into place. This is kinda hard to explain so i drew a really shitty picture in paint to illustrate. So then ya bait this bottle and possibly put a little piece of live rock in there so it doesnt blow around your tank.

The fish will then swim in for the food and for some reason be unable to swim back out. I dont know how big your damsel is so you may have to cut a bit back off the mouth of the bottle, but dont make it too big.

Only downside to this plan is you will most likely catch other fish first. Be patient.

Ive had other friends that actually fished in their tank with tiny hooks to catch annoying damsels.

I had a damsel problem myself once. Then I bought an angler. :)

@uberbatman
Fish traps are funny like that. Same with lobster traps. They can get in but are confused at how to get out.

@uberbatman thanks for the tip, Im going to try the bottle trick, I actually did go fishing in the tank today and of course did not catch him..I ended up catching the clownfish! Luckily he wasnt hurt at all. I will definately attempt the bottle ttrick though.

The damsel was all my fault,, I went snorkeling and caught him with my hands and thought “I’ll put him in the tank” I think I thought it would be neat to put a fish I caught bare handed in my tank…well lesson learned, I won’t be doing that again. The only other fish I have put in my tank I caught with my hands is Molly Miller Blennies, theyare harmless and fun to watch and they actually eat algae :).