I've been treating my turtle off and on for fungal infections for some time now. However any time there's an improvement and the treatment is stopped, the fungal infections start coming back.
While I do clean her tank regularly (once a week), I suspect that the filter that I have is incompatible with the tank even with the regular water changes so I've been looking to buy a better one. The tank holds about 40L of water, I've asked in a local store about a more powerful filter and they told me not to buy one meant for a bigger tank as it may push the turtle around or something like that (which I kinda doubt would happen).
This is what my setup looks like: https://i.imgur.com/eZW4SOX.jpg
I have also found these filters in the local store, I'd very much like to get an opinion on which one would be the best for my tank:
https://www.fish-street.com/resun_cy20_ ... tring=cy20
https://www.amazon.co.uk/Aquarline-Comp ... B00HB2JR3Q
https://www.amazon.co.uk/sera-30603-Fil ... B002O82LEO
https://www.sera.de/us/product/freshwat ... l-filters/
https://www.sera.de/us/product/freshwat ... ix-filter/
https://www.fish-street.com/resun_ef600_external_filter
https://www.amazon.co.uk/Minjiang-Diamo ... B014DWRNLY
As for the fungal infections, I've taken photos of the infected places and have posted them below. I've also resumed treatment that consists of cleaning and brushing the turtle, followed by a potassium permanganate bath for several minutes, then applying iodine to the affected places and finally rubbing a paste made out of neosporin, silver sulfadiazine, clotramizole and betamethasone, after which she is dry-docked under a heat lamp, this treatment has been effective in the past, although I am not sure if I am to apply it everyday or not.
Here are the images of the turtle:
https://imgur.com/a/DrhECPG