Help!! My molly fish has weird green stuff growing all over it!

[Deanna]

Hey guys, I need some help. My molly fish has weird green stuff growing on its fins. I noticed this when my Molly fish went really close to the lights at the top of the tank, and when the lights shone through her fins it exposed this weird green stuff on her fins. What is this stuff? Is it harmful? If so, what medication do I have to buy? If you need pictures just tell me. Thanks!

 

[FreshyFresh]

Did you recently purchase this molly?

What size tank? Other inhabitants?

Do you have a read in PPM for ammonia, nitrite and nitrate?

Sorry for all the questions, but they're needed to help.

 

[Deanna]

My molly is kept in a 5 gallon tank with nitrite snails. I don’t have read in PPM for anything. I purchased this molly about a year and a half ago.

 

[FreshyFresh]

Any recent additions to the tank that could have brought in an illness or parasite? This includes live foods.

The reason I asked about your water parameters is it's high nitrates can cause issues like you describe. Nitrates creep up daily and are only reduced by doing water changes of 50% or more per week.

 

[Deanna]

So, should I get a freshwater test kit? And if nitrites are high should I start doing 50% water changes?

 

[FreshyFresh]

Yep. Anyone in the hobby should have something along the lines of the API master test kit. They're cheaper to get online, but can be had for $30 or so at chain pet stores, etc.