Just plati dying off

[Stryker]

This isn't exactly an emergency, however fish are dying. Ammonia and nitrites are nil, nitrates for a couple of weeks were around 100 but these last few days I've had them down to 40ppm, soon to become 20ppm when my RO unit turns up.

The PH is the usual 7.5ish and the water is well oxygenated. (at least it is now since my platy started dying off).

Over the last few days the majority of my platy have been looking really lathargic. I've observed some also lapping at the water's surface. Some sit around on the bottom, some only move a little, others are fine. I've had a couple die and now I think more are to follow.

All I've added in recent weeks were 3 clown loach. Well one died for reasons unknown (those little fellas have a rough time in transportation).

I've even found some of the platy to have a little white spot, although this I think is only because they are so weak.

My other fish are totally fine.

Ideas?

 

[WILDER]

I would try anti internal bacteria med in your tank.

 

[OohFeeshy]

I'd agree, I think my guppies died of that.

 

[Stryker]

For the time being I've just added the white spot meds as thats going to weaken them even further. I've also raised the temp.

I'd seperated the sickest plati into the sump tank so there is no risk of bullying from other fish, plus they will be easier to remove if they die.

However this morning, they are looking a little more perky. A boost to the tanks oxygen seems to be helping them.