Hello, I have had two Macleay River Turtles for over one month now, and I found something on one turtle's shell. A few days later I noticed the same problem initiating on my other turtle. I then immedediately called my aquarium and was told to apply betadine on their shells every two days when dried (after I described the issue). It has been one week now and the issue has gone down slightly, but not entirely. I change 50% of my water twice a week, and only recently had the readings: Ammonia - 0 Nitrite - 0 Nitrate - 10 pH - 8.0 I have been feeding them a range of foods every day. This includes frozen food such as brine shrimp, to live foods such as crickets and mealworms. They have a dozen feeder fish in the tank, however are still too small to eat them (few months old). They are both very active, always eager to eat and bask on their dock everyday. What is the problem, and how do I resolve it? Kind regards, Dylan.