Fishy Fungus

Sorry to read about you having ammonia problems. If you aren't doing so already, it's always worth quarantining new fish - and a spare tank comes in handy for hospital or other isolation purposes. https://www.thinkfish.co.uk/article/isolation-hospital-or-quarantine-fishtanks-for-your-fish and https://www.fishkeeper.co.uk/faq/do-i-need-to-quarantine-my-new-fish-and-if-so-how-do-i-do-it/  I have a plastic tank which can be easily stowed away with its contents for such scenarios.

When using a quarantine tank, mature filter media can be taken from the main tank's filter and used in the quarantine tank, then added back into the main tank's filter later. Alternatively, a spare filter can be kept/used in the main tank and taken out as and when required for the quarantine tank. These scenarios should hopefully avoid any ammonia presence in future, and in turn the sorts of problems you've been encountering due to the filter having insufficient bacteria to support the bioload of the fish.

Pristine water quality at all times is the best cure - 0 ammonia, 0 nitrite, and <20 nitrates. Otherwise, eSHa 2000 or Waterlife Protozin/Cuprazin might be suitable options. Edited to add: NT Labs and Interpet also seem to do treatments for fungus. I have used Easylife Voogle on a fish that had an ulcer and often grew a saprolegnia-like tuft of fungus on the top, like the cotton that falls off trees - it did succeed in causing the fungus to fall off, from recollection, but the problem was recurrent.

Hope this helps. 

Thank-you, I will try protozin and put the fish in my quarantine tank i think.

I bought a external filter, fluvial 207 a few weeks back and have practically tripled my media compared to my internal filter I had, so have just been waiting for the bacteria to grow enough to sort my problem out, I think the seachem stability has sorted that out now though i am ammonia free

My friend says aquarium salt can be a good treatment for fungus too?

I will try the other stuff first then salt if still no luck thank-you 

Probably bacterial if Protozin hasn’t cleared it. I’d try Myxazin.

I wouldn’t add salt to a tank with Corys in. Salt baths only for them, but it doesn’t seem like a fungal issue so salt wouldn’t be advisable.

My bad. Thought you had Corys for some reason.

I do but they're in the main tank