Sick platy...

[Booboo puppy]

I just did a 10% water change this morning. Before the change, the nitrate was 20, the nitrite was .8, the PH was 8.4. Don't know about the ammonia, not part of the test set I have.

This evening Mama Platy is out of the cave where she has spent a lot of time. I thought she was just trying to avoid Daddy Platy. She is swimming at the top of the tank, at an angle with her tail lower than her head, and her tail is not fan shaped any longer, but straight out from her top and bottom. Auntie Platy is following nearby, not chasing her, and when Daddy Platy tried to investigate, Auntie Platy chased him away. The tail doesn't have any white spots nor are the edges black. Is this fin rot? Is that contagious? Does she need to be quarantined? Medicated?

Any advice greatly appreciated.

 

[Tolak]

The problem is the nitrites. They should be at 0. Nitrites inhibit a fish's ability to process O2. Sounds like she is looking for more air. You can either drop the water level if you have a hob filter to create more surface disturbance, or add an airstone.

You should find out why you have nitrite present. It means eithe a mini cycle in an established tank, or a newer tank that has not fully cycled yet.

Tolak

 

[Booboo puppy]

The water is low enough that there are constant bubbles from the filter. I'll check the nitrite again this evening to see if it's still .8.

edited to add: Nitrate is 20, nitrite is 0, total hardness is 150, total alkalinity is 180, and PH is 7.8. Ooops - Nitrite was .5 this morning before the change, not .8.

 

[Tokis-Phoenix]

How many gallons does the tank they're in hold and how many/what types of fish does it hold? Find out the nitrite and ammonia ASAP.
Do the fish appear not to be able to maintain balance in the water/stay upright?

 

[Booboo puppy]

40 gallons - 1 male platy, 2 female platys including the sick one, 9 baby platys, 3 cory, 6 harlequins. Only the one platy seems ill. The others are active and seem to be getting along with each other very well.