Platies are flashing!

I have a 30 gallon aquarium with 3 platys, 3 black mollies, an about 10 babies. ammonia 0ppm
Nitrite 0ppm
Nitrate 25-30ppm
pH 8.0

I am seeing a few platys scratch againt decor and am beginning to worry. I am currently treating them with melafix to help them with their fins. One of the platys fins are damaged, and the mollies fins are losing their black color/fraying. I think they have fin rot, but how the tank is fine? What could be the problem?? All help is very much appreciated!

 

Have you added anybody new to the tank? It's possible you're on the verge of an ich outbreak.

Otherwise a water change and a good cleaning are your first line of defense against most tank troubles.

It would help to post some photos of the affected fish to pin down the root cause.

 

Sharp decor can cause it, as can a bully, but if all you have are the mollies and platys, that isn't likely.
Are they new(er)? They could be recovering from ammonia exposure from the fish store.

 

I have had them for 5 months. And have not added anyone new recently

Sharp decor can cause it, as can a bully, but if all you have are the mollies and platys, that isn't likely.
Are they new(er)? They could be recovering from ammonia exposure from the fish store.

Could it be the melafix I am putting in the tank?

 

I have no experience using melafix or its cousin, but I've never read any account of it causing those symptoms.

40 nitrates is the top end of what fish can tolerate. I would do a 50% water change to bring them down to twenty and do them as frequently as needed to keep them there. Good water is usually the cure all for fin rot. I say usually, as secondary infections can occur (that's what the melafix is for).

 

Hello Jon...

Aside from using a water treatment, you don't want to put chemicals into the tank water. You don't know how the fish, plants and the good bacteria will react. Flashing doesn't necessarily mean the fish have parasites. They rub against plants and decorations to remove small bits of algae they eat to supplement their diet.

The best thing to do is to make sure your fish have clean water. Small tanks really need large, weekly water changes. If you're not removing and replacing half or more of the water weekly, then you should work up to that point.

I keep larger tanks with mostly livebearing fish like your Platys and Mollies. I add a bit of standard aquarium salt to the tank water, usually a heaping teaspoon for every 5 gallons of new, treated tap water. I've found the salt helps keep all the fish healthier, but this is up to you.

Keep the tank water extremely clean and you'll have a healthier tank.

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