I had similar problem with my hatchling ally snappers. first I thought it was shell rot and treated with antibiotics, antifungals, antiseptics, salts, dry docked etc. But nothing helped. I had lots of mopani wood in my setup. Then I removed the woods and stopped treating, then the problem stoppped. The lost tissue did not heal up but, did not get worse too.
Then I have spoken to a chinese turtle breeder. He said that the problem was due to low ph. When I had woods in tank, my water was not low in ph because of regular water changes. But it was very high in tannins. It was almost dark brown.
I have seen your post when I was in search for a solution. You have a large wood in your tank too.
I have a theory, every source says ally snappers prefer soft water. But all videos taken from their natural habitats shows crystal clear water, no yellow or brown water.
I think the problem is tannins, not the ph. Tannins released from decorative wood known to protect fish, harden the skin of fish, prevent fungus and slows down slime coat production. Since ally snappers' shell is covered with a kind of skin unlike other turtle specieses. Tannin may have a negative impact on ally snappers. I got four more ally snappers after my first two with shell problems. And used only inorganic material in their tanks. No wood, no substrate. And they are growing up with no shell problems.
Here are the links about my topic, the external link has much more photos.
http://www.monsterfishkeepers.com/forums/threads/alligator-snapper-shell-rot.609673/
http://www.turtletimes.com/forums/topic/80443-alligator-snappers-loosing-scutes/
Then I have spoken to a chinese turtle breeder. He said that the problem was due to low ph. When I had woods in tank, my water was not low in ph because of regular water changes. But it was very high in tannins. It was almost dark brown.
I have seen your post when I was in search for a solution. You have a large wood in your tank too.
I have a theory, every source says ally snappers prefer soft water. But all videos taken from their natural habitats shows crystal clear water, no yellow or brown water.
I think the problem is tannins, not the ph. Tannins released from decorative wood known to protect fish, harden the skin of fish, prevent fungus and slows down slime coat production. Since ally snappers' shell is covered with a kind of skin unlike other turtle specieses. Tannin may have a negative impact on ally snappers. I got four more ally snappers after my first two with shell problems. And used only inorganic material in their tanks. No wood, no substrate. And they are growing up with no shell problems.
Here are the links about my topic, the external link has much more photos.
http://www.monsterfishkeepers.com/forums/threads/alligator-snapper-shell-rot.609673/
http://www.turtletimes.com/forums/topic/80443-alligator-snappers-loosing-scutes/
