Hi all,

I'm not new to fish keeping but new to Marine keeping. I've kept all sorts of freshwater in the past, with no great issue.

My new Marine tank is around nine weeks old. I used tap water to start (as my original plan was for fresh, changed my mind early on) so treated to make seawater. I have a ton of Live Rock, added arond three weeks in. The tank seemed cycled around six weeks in so I added two Cleaner Shrimp, two Hermits, and two Turbo Snails. The tank seemed very stable, the Clean Up Crew are absolutely fine, and the Live Rock has spawned more wildlife than I ever imagined possible! - no issues at all.

Having performed a 50% water change (with water from the LFS) and everthing looking settled I decided to add two tiny little Clowns. The first Clown looked ill as soon as I added him - his fins were ragged and his skin seemed flakey. I assumed the LFS man had sold me a duff, but he died before I could take any action - he only lasted around 4 hours! The second Clown, who was full of life the first night developed exactly the same as the first the second day - listless, and ragged skin. I've never seen a fish fall ill and die so quickly, and i've kept all sorts!

Now I dont know what's happend! The tank was cycled, the water seems the same as the LFS, but the fish just died! I feel awful for the poor little dudes, and I'm certanly not going to make the same mistake again but I need to know what went wrong.

Can anybody help please?

I would suggest you compare your tank's water parameters (hardness, salinity, temperasture, nitrates and ph) with those of your fish store, something is very different. My experience with Clowns is that they are very sensitive and not nearly as tough as Damsels. I would not add Clowns to a newly cycled tank, Damsels are much better.

Everything should be the same, as the water and fish came from the same place (obv not the original, but 50%)

The weird thing is the Clean Up Crew came from the same and are doing fine?

One thing though, the temp was way up. After I bought the fish the weather just went mad - the tank temp shot up - could this cause such a shock as to kill the poor things only hours after introduction?

Yes, the temperature swing could have killed them.. but, did you properly acclimate them? did they look healthy in the lfs tanks? Watch your tank at night to make sure you dont see any bad hitchikers like rock crabs. They're known to kill or attack fish. If the clowns were tank raised/born, they should have been a bit less sensitive. What are you water parameters? Numbers helps so see if you can get some for us.