Gorilla Crab and other issues with fish

[Guest]

So our clown is almost completely ich free and acting pretty healthy. Unfortunately, we've lost the tang (within 3 days of purchase), our starfish, and 2 damsels. Water quality is good and cycled. We've been maintaining a temperture of 76 for a couple days now. The strange thing is the fish are all dying in the same period of time and seem perfectly healthy the night before. I just don't know what is going on. Something is obviously suddenly wrong with the tank, but the clowns are completely fine... if not better.


Another bizzare thing was we were feeding our fishand out of nowhere furry little legs pop out of our live rock! Eek! Turned out it was a full crab! After a quick call the aquarium store and a little online research... it's a gorilla crab and it could get big! and be mean!

Advice?

 

[melosu58]

Time for the old tilted glass trick. Get a glass and put it in your tank and have it tilted so the crab will walk down to the food at the bottom but he wont be able to walk back up because of the slippery surface. I ve seen this work many times.
Also can you give us some water test results of your tank. You`ll need to QT your fish and keep main fishless for 8 weeks to break the parasites life cycle. You`ll also need to treat the fish in the QT using either copper or hyposalinity.

 

[roka64]

Can you get a pic? He should have black tips on his claws and be very hairy. I would do as mel said. I am also curious about your test results. If you have ich, I would not place any new fish in the main tank for 8 weeks and QT/treat your current fish.

 

[Guest]

He went into hiding last night... we can't find him, so no pic. We only have our pair of clowns in the tank right now and they're completely healthy, but we're still on the Kick Ich cycle treatment. I want to get that crab out soon! I'm afraid it might munch on our little shrimp. We've already lost a damsel and we've checked the filtration and underneath rocks and so forth... no where in sight.

In other news... added new live rock today.We found a set-up for a QT for $60. What's the best way to cycle a tank? The guy at the store told us to buy small live rock and some damsels, but I've read about dropping a raw shrimp and letting it decompose. I really don't want to put any live critters in our cycling QT.

Also... good algae, bad algae? What do you know?

We're waiting for our QT to be up and cycled before we buy new fish. This might be a while because of Christmas. After our Kich Ich treatment, we're probably going to buy a new seastar and shrimp. Eventually we want to buy a school of yellow tangs, but it will be a long time before we add new fish, if my boyfriend and his sister listen.

Test results-
Ammonia- 0
Nitrite- 0
Nitrate- 20
Ph- 8.3
Salinity - 1.021

 

[roka64]

Props on not putting some poor damsels through sewage conditions in the QT. I am using a raw/unseasoned shrimp in my QT, right now. Basically, in order for a tank to cycle, you only need to add an ammonia source. This could be rotting food/rotting shrimp, fish waste, bassically anything that can rot and produces ammonia.

Also... good algae, bad algae? What do you know?

What kind of algae are you wondering about?

 

[Guest]

We have a brown with red tint algae growing in our tank. I'm wondering if this is good algae because our little tang died and I want to make sure it wasn't the algae he was eating.