fish dying

[mastewar20]

Over the last week all of my fish have died in my tank. I do a 15% water change weekly and replace with RO/DI water. I have a 75 gallon tank, and had 2 clown fish (deceased) 2 cardinals (deceased) 4 damsels (3 deceased) 1 scooter bleeny (deceased), 1 fire fish (deceased) and one puffer.

The chemistry is as follows:
pH 8.4
PO4 0.25
ammonia 0
nitrite 0
nitrate 20

I did upgrade to a bigger tank about 1 - 1.5 months ago. I had a 55 gallon and upgraded to this 75.
I don't see any signs of ick or anything else as far as I can see. They looked healthy and then one by one they are dying. this has been going on for about a week. The only thing different is I got a puffer and he looks healthy.
I also put a carbon filter and ammonia neutralizing filter in my sump.
any suggestions? Need help

 

[monkeysee1]

Your puffer was stressed with the move I think. Stress causes this fish to release deadly toxins that will kill other fish. This is what I suspect happened.
Sorry for your fish.
Change your carbon every other day for a couple of weeks before adding anything else.
I would steer clear of puffers from now on.

 

[JUNBUG361]

P04 & nitrate are high, is the readings before or after the water change & fish?

 

[mastewar20]

P04 and nitrate have always been these levels. for almost 2 years. don't know how 20ppm of nitrate is high. almost impossible to get it to 0

 

[elecbzerk]

I've had multiple puffers that I've moved tanks a couple of times and they never released toxins that killed all my fish, they made the tank moves just fine. I agree that something stressed them but I think the answer lies somewhere else. Is the 75 new? I am assuming you used water from the 55gal and just added what you needed to fill the 75. tell us about your filtration, comparison of the 55 and 75.

 

[mastewar20]

In my 55 I had 2 fluval HOB filters. When I received the 75 I bought a sump. It had bioballs in it. I use filter material for incoming water and a carbon filter. The tank was second hand however I did rinse it out very well. Yess I used the same water from the 55 to fill. And then just added water as needed. This tank has been in service for over 2 months now and it looks like it is starting to cycle. The anemone looks to be very healthy as well as the snails and crabs.

 

[emilese]

Is your puffer the newest member to your tank? What kind of puffer? What kind of signs did your fish display before dying? Did they seem healthy one day and dead the next? Or, did they slowly decline? Did they have bite marks? Torn fins?

Puffers can be very aggressive (some more than others). Could your puffer have taken them out?

 

[mastewar20]

Yes the puffer is the newest. The puffer is green with black spots. the fish that died died very fast, looked healthy one day and dead or dying the next. didn't really see any torn fins but really didn't look that much at them after they were dead.

 

[Joshua I.]

Sounds like it might be the puffer sometimes if it is a aggressive fish you can remove it or add fish that can take care of themselves or feed more that might make him cill out. If it is him even it might not be.

 

[Joshua I.]

btw make sure there isn't anything unwanted in the tank like a pistol shrimp or a gigantic worm that will try to eat the other fish.

 

[Uncle99]

You describe either a poisoning, no oxygen, or infection of some type.
As an example, Untreated velvet or metal leakage can result in total death.
Sorry for your loss, sometimes we find the answer, sometimes not....that the hobby..

 

[lagatbezan]

sorry for the loss
As far as I know puffers don't release any toxins. Cowfish/Boxfish on the other hand do.
you might have a parasite in the tank like velvet which is a super fast killer. Uronema is another one that comes to mind and it usually shows up as red lesions on the fish's body specially with chromis and anthias. hopefully thats not what you are dealing with!
do you have good water movement/oxygen exchange in the tank? if you do then my guess would be some sort of parasite or disease.
Were the fish qt before going into your display? If not, now would be a great time to set one up and put the puffer in it while having your display go fishless for 76 days. This will eradicate whatever it may be (except uronema) out of your display and you can treat the puffer in qt if needed.

 

[heathlindner25]

sorry for the loss
As far as I know puffers don't release any toxins. Cowfish/Boxfish on the other hand do.
you might have a parasite in the tank like velvet which is a super fast killer. Uronema is another one that comes to mind and it usually shows up as red lesions on the fish's body specially with chromis and anthias. hopefully thats not what you are dealing with!
do you have good water movement/oxygen exchange in the tank? if you do then my guess would be some sort of parasite or disease.
Were the fish qt before going into your display? If not, now would be a great time to set one up and put the puffer in it while having your display go fishless for 76 days. This will eradicate whatever it may be (except uronema) out of your display and you can treat the puffer in qt if needed.

The voice of reason...