Declining Clown Fish

lararose · Apr 30, 2026

Hey everyone,

I have a little clown in a new nano tank that has been declining since day 1 of me putting it in the tank. I cycled my tank for 2.5 months before I was sure it was ready for fish. I used cycled bricks and ceramic balls from a local fish store which I did for my main tank as well. I got him 5 days ago but since introducing him into this tank he has eaten maybe twice. I was quite concerned he would not accept frozen food. It’d spit it out but I saw him eat 2 pieces. Then I tried pellets on maybe day 4. He was very interested and ate 1 in the morning and 1 at night. I thought that was a positive sign until I woke up this morning and noticed him hovering around the bottom of the tank and rapidly breathing. He is losing a lot of his colour too.

The basic parameters are

Salinity 35.7

Nitrate 11.3

Nitrite 0

Ammonia 0

Temp 26.4

I have tested these parameters and made sure they’ve remained consistent. I have also got another 200L tank which I’ve had for about 10 months so it’s not like I’m exactly new to this. But I have no idea why he is declining and what I’ve done wrong. Just hoping for some insight so I can hopefully save this little guy. Thanks.

MikeyZo · Apr 30, 2026

How much surface agitation do you have? Maybe not getting enough oxygen? Also, I always ask the lfs if they can feed the fish so I can see it eat before I purchase it. Sometimes wild caught don’t do well with the transition. I had a clown that lasted 2 months… I never saw him eat. Frozen, pellets… the only thing he ate was live baby brine shrimp but that wasn’t sustainable long term for me. But it’s worth a try for you.

Also, your salinity is a little high. If you just have the fish I’d shoot for closer to 33-34. 35 is good for SPS. But if you’re gonna lower, lower slowly

Fish Fan · Apr 30, 2026

Welcome to Reef2Reef!

#WelcometoR2R

Sorry to see your fish in distress!

Did you notice any signs of possible infection, like white spots or labored breathing?