Could anyone advise on fungus and/or my test results...

[4yoniD]

I have a tank with platies and 2 corys. One of my platies has white markings on it's head which I think may be fungus? It seems to be getting slowly worse. I had a google and the suggestions were bad water quality. I bought a test kit and my results are ph 8.0, Ammonia 0.25, nitrite 0, nitrate 0. Is the ammonia a problem? I know the ph is high but understand platies don't mind. Temp is 25. This is the results halfway between the weekly 20% water change. Any suggestions? Thanks.

The ammonia isn't massively high- it should be zero but might just be the test. It's weird that the nitrAte is zero though, I would expect to see a reading for that. How big is the tank and when did you last clean the filter?

60 litre tank, I rinse the filter sponge in tank water every 3 weeks and its probably due.

How many platys are in there? Is it heavily planted?

The higher the ph the more toxic ammonia is. Is it the API test kit you have? Look down through the test tube for the ammonia for the best result (i spent weeks thinking i had a trace of ammonia, but i was told to do this and it'd been 0ppm all that time!) Try to source some Esha 2000, its natural so doesn't harm the filter bacteria. ALso if it is the API test kit, when you do the 2nd bottle of the NitrAte test make sure you give it a few knocks on the floor/wall and shake it for a good 2 mins as the crystals in it sometimes crystalise so you dont get a clear result. HTH.

It is the API master kit. I shall try the top-of-the-test-tube thing. I'm more worried now you've said about the ph affecting the toxicity! Am going to retest on Sunday before I clean the tank.

I don't know how many platies . They had babies and they swim around too fast to count. My tank is probably over-stocked if you count them as adult size, but they are much smaller. Some will be rehomed when a bit bigger. Tank not heavily planted, just some camboba (cabomba?) for them to nibble.