9 Fish Gone in Days!

[Sasha]

My 29 gallon tank is going through a major crisis with an unknown cause! During the past 9 days I have lost: 5 black mollies, 2 male guppies, 1 male swordtail and 1 balloon molly. I have no clue to what's causing their deaths. They seemed fine one day and the next day they were dead. My tank looks so empty!

The 29 gallon tank has been running for more than a year with an Aquacler 200. The heater is set at 78 degrees. I clean the filter once a week with the tank water and do a 20% water change. I add aquarium salt and water conditioner into the new water.

Ammonia is at 0
Nitrite is 0
pH is 7.0
Nitrate is 12.5 (I just started doing a few water changes to bring them down a little)

I asked in Petco to see if they can give me any suggestions, but they just said they have no idea what going on because they never heard of this probelm. Any advive?

I also posted another post under "fish emergencies", but I need to see if anyone has any livebearer knowledge to help me.

 

[QHowes]

get any surviving fish out of the tank...replace charcoal and sponge aswell as your gravel and start fresh. dont forget to cycle.

 

[MartinB]

I have read your other post.
I think you should stop adding aquarium salt.
I have never used it.
I only got my first tank 2 years going and out of the 10 fish I got 2 years ago I have only lost 2.

 

[guppymonkey]

The aquarium salt would only be a problem if the fish weren't raised in water with any salt or if too much was added. Since you didn't say how much you added I can't suggest either way about the salt.

The nitrate is obviously very high. I am not sure how high nitrate has to be before it becomes harmful but I think your levels are dangerous. The water changes are a very good idea. I change my water (usually about 10 to 20%) twice a week. The fresher the water is the better off the fish usually are. If possible maybe you could get some live plants to help alleviate the high nitrate problem. I don't know what else to suggest except to keep an eye on any remaining fish to see if its a virus or bacteria that is killing them off instead of the nitrate.

 

[Sasha]

I only add aquarium salt into the new water. I read mollies need salt in their water, but I'm not sure if that's true or not. I have a couple live plants in the tank, but I could never keep many plants alive. I'm doing water changes daily to try to lower the Nitrates down. Still, I have no clue to why the fish are dying at a rapid rate!

 

[MartinB]

I have also read mollies like a bit of salt.
But thay also can go without it.
I would do 20% water change for the next 3 days with no salt and leave it for 4 days.
If more fish start dieing after that week is up, you know it not the salt.
Also put a few more plants in.
My plants only live for 3 to 4 weeks.

Edit:= have you put anything new in your tank in the last 2 weeks?
Like rocks??

 

[pondfreak4365]

I have no ideas, but I don't think a Nitrate reading of 12.5 is high at all. Mine out of the tap is around 25.

 

[Sasha]

I bought 3 new fish after the first fish died. Now, I'm thinking that one of those fish carried a hidden disease which quickly spread to most of my other fish. That's the only thing I can think of because the water tests out fine, but I'll continue to do water changes for a few more days. Besides that thought, there is nothing else I can think of to cause so many fish to die.

 

[guppybaby]

you might also want to add something called proquatics water conditioner. it contains aloe vera and helps in the healing of damaged fish tissue. you can find it at the lfs. it is also known as a stress reducer. please let us know how things are going. good luck

 

[guppymonkey]

you might also want to add something called proquatics water conditioner. it contains aloe vera and helps in the healing of damaged fish tissue. you can find it at the lfs. it is also known as a stress reducer. please let us know how things are going. good luck

Most water conditioners have stress reducers in them. I use Stress Coat personally. I don't think they would help in the case of a disease though. Its very hard to tell when fish are sick until they are extremely ill and its almost impossible to diagnose most illnesses. Water changes would be the best solution I can think of. Fish always love new water.