New Fish Keep Dieing In My Tank

[fish killer]

Hi
I Have a 190ltr 3 year old tank and have had two percula clowns cleaner shimps a fire shrimp snails, red leg hermits and several corals these have all been in the tank some time with no issues apart from loosing the odd snail here and there. Every time i introduce a new fish it dies some last a few days some a couple of weeks i have tried blennies cromis gobies a wrass a flame angel a coral beauty and a tang all to no avail any ideas on what is going on. I have tried baiting out to see if there is any preditors in the tank but have had no joy and have heard or seen any tell tail signs. thought the o2 level in the rockwork could have been low when the fish rest at night so i aireate the water when i do water changes to ensure the o2 level stays high. I Have just introduced a pair of torpedo gobies and the clock is ticking ANY IDEAS ??????

 

[melosu58]

You aerate your tank by surface aggitation. Not quite sure how you`ve been doing it? Just take a PH and point it slightly to the surface and aggitate the surface. One thing we have to have is water test results.

BTW moving this to the sick fish forum.

 

[austinsdad]

So, you only have two previous clowns for some time that live and ALL the new fish die?

How are you finding your dead fish? Sickly the days/hours before or very healthy and eating? Or in pieces have died some time ago with crabs eating at them?

Yeah, water readings will help. Also, tell us how you've acclimated the new fish. How many days after intro are they dying too? Sorry for so many questions, but we need lots of info to help narrow down the cause.

 

[fish killer]

Nitrate levels are at 20ppm and ammonia levels are at 0.5 these are the worst readings i get for these PH is usualy around 8 changing dependant on the time of day. I have been running an air stone through the RO water before doing a water change but always have a power head and the outlet of my canister filter breaking the surface water.

 

[fish killer]

aclimatise them by floating them in the tank and adding around 50ml of my tank water in to theres every 15mins for around 1 to 1 1/2 hrs. Mostly the fish seem healthy and feeding there have been a couple of fish that i have never been able to find presumed that they had been cleaned up by the crabs and shrimps for a time i suspected a preditor but have spent a lot of time searching and baiting and not found anything several of the fish i didnt see for about a day so searched for them and usual find them being picked at by a shrimp found a couple of them whole before anything got to them. Some have died a few days after introducing them and others have lasted up to a few weeks and just when i think they are settled they die.

 

[austinsdad]

If you've got ammonia in an established tank with fish, there is something very wrong. The clowns may have grown accustomed to the change since they were there before the problem. Besides, they're damsels and have cycled many a tank (old school, but no more). That's whay they only live.

Didja change any rock around or add new rock recently? Still wondering how your coral is surviving in the ammonia. Wondering how the ammonia happened.

 

[fish killer]

I have not added an new rocks recently. the ammonia level is generaly below 0.5 but at its worst it can go that high. I always thought this was just part of the cycle of a tank and waste products caused ammonia is that not the case?

 

[mfdrookie516]

you will always have a source of ammonia in a tank with living creatures in it, but the bacteria should convert it to nitrite, then to nitrate. in a tank that has been running for 3 years, you should never have any readings of ammonia or nitrite... if properly stocked and maintained...

 

[fish killer]

Very nice looking tank mate. and cheers for the help with this. any tips for keeping the ammonia down i have active carbon in my canister filter and in a filter pad in an internal filter that generaly dose the job and when it starts to creep up again i change them but will make sure i keep on top of this if it could be the cause the shrimps and coral are still aok and the coral is grate i have a mushroom sporning new ones regulary and a finger sponge that i have fraged several times as it keeps taking over the tank as well as variouse other mushrooms cabage coral and bubble coral.