Help, fish dying in my aquarium

[ladyhawke]

Hi,

I have a 30 gallon tank that has been set up for a couple months. I was careful and cycled the tank when I set it up. I kept a close eye on ammonia and nitrites.

In the past four days I have lost all my platies and three of four of my cory cats. All that is left now are 6 leopard danios and 1 cory.

They were all doing fine and seemed perfectly healthy. Then every morning I would wake up and find one or two of them dead. I checked the ammonia and nitrite again and they both came up as zero. The pH was 7.0. When I set up the tank it was at 7.6 but I know 7.0 is a good neutral number. They never showed any signs of being sick.

Any ideas as to what is happening?

thanks in advance!!

[Incredulous_Ed]

Perhaps the temperature is off. Is there any signs of soap in the tank? soap will kill fish. did you do anything to the tank recently?


Either that or there is an evil shark in the tank!!!

[ladyhawke]

No, the temperature is at 78 degrees until the temperature gauge is wrong. No, there are no signs of anything like soap in the tank. The only things I have done recently is change the water and added a few live plants a week or two ago.

I change about 20-25% of the water weekly. I was thinking maybe it is high nitrates. My test kit did not come with anything to test for nitrates?

Definitely don't have any sharks in the tank unless they are invisible!!

[Incredulous_Ed]

Perhaps the live plants brought in a disease or parasites, if that's possible. Is one of the fish picking on the other fish to a degree that they die?

I dunno, try removing the plants and see if that helps. You should probably ask william, he's the expert!