Stumped...Need HELP!

[Mailbox]

Hi there.

Newbie looking for some advice. I set up my 12 gallon saltwater FOWLR in June of last year. For the first 4-6 months things went great. My water was clear, my fish seemed happy and healthy, overall no problems. Then one by one my fish started dying. I should restate that...they started disappearing, never to be heard from again.

I always started with the beginner fish and was as patient as I could be. I did not add more than two at a time, never bought more than two per month and I drip acclomated them over about an hour period. I have lost damsels, a sea star, and 2 a pajama cardinals over that period of time. EVERY time I check the stats on the aquarium they look great.

At this point I really am gun-shy about putting anything in there. The only living things in there currently (for about the last month) are a few snails (2 astrea, 2 nassarius), I would guess bacteria and otherwise not much else. My live rock is covered with coraline which I have fun scraping off the walls of the tank.

Not sure where to go from here. I guess it's possible that there is something in the tank killing the fish, but if there is it's in the middle of the night but I don't see much in the line of movement except for some long white antennae that wave around out of my live rock (I think they are spaghetti worms).

I should also add that the last fish I added were two domino damsels. They were gone within one day.

Here's my stats: from about half an hour ago:

Salinity 1.025
80 degrees
PH 8.4
Alkalinity 2.3
Ammonia < .25
Nitrate ~ 10
Nitrite 0

Anyone have any ideas at all?

 

[melosu58]

This is the reason I hesitate to encourage people to have a small tank. Everything looks good in the beginning but several months later everything goes haywire. Smaller tanks with their less water volumes are less forgiving. Small mistakes or non diligence can be disasterous in a small tank.
Saying all that I`m not saying that`s the case with your tank but you`ll need to stay on top of the tank if you continue with it. Everyday top offs and less feedings. Daily or at least every other day water tests. Your readings look OK provided that ammonia reading is zero. If it was .25 or close than that would be bad. I would not add any more damsels in that tank.

 

[Krypt]

Have you heard any clicking sounds coming from your tank by chance? If you do, then you probably have a mantis shrimp in there that hitchhiked in on your LR. Another thing you can do to find out whats happening at night is get a flash light with a red lens and use it to search the tank at night to see if you have any unknown tank residents. If they are disappearing it sounds like you have a predator in there somewhere.

 

[mrg02d]

Im guessing its a predator. Damsels are pretty tough fish! People cycle with them for that reason.

And to have them dissapear only strengthens the theory of a mantis shrimp. (They are VERY intelligent jerks).

Wait 2 hours after complete darkness and look in with a red light. You might consider some kind of bait to lure the enemy out.

Matt