Glad to hear you trying hard to help your little friend have a good life.
It may have been a while since you have had turtles and you may not know that there are now some (not many) very well-trained reptile veterinarians out there and it is considered standard practice to bring any new turtle to a vet as soon as you get it unless you are well-versed in the disordered of turtles yourself.
Its good to get a check up as mnay new animals are harboring parasites and have been stressed by the pet trade.
try:
arav
click on thr members link and find a vet near where you live. DON"T take your turtle to a dog or horse vet. The truth is they really don't often know all the details.
My other simple observations would be
(1) a constant 85 is not ideal. A air-temp gradient from about 72 - 90 is better. keep the warmest area well-lighted as turtles are inclined to seek light for thermal regulation. Keep the water near 75 - 78
(2) a hiding place in the water and on the land is a good idea for a semi terrestrial like a ambo. use carefully arranged rocks or pieces of wood.
(3) live plants help provide cover
(4) ambos love melon of all sorts and will eat water plants too.Get some canteloupe, honey dew, Go to a pet store and ask for anacharis or elodea water hyacinth water lettuce or duckweed....better yet look up photos of these first as pet store employees may not be able to identify these plants. And try a pond store or garden shop as well.
(5) I don't know how big the enclosure is but the bigger the better. I would think 6 square feet would make for a good minimum size. So a small fish tank is not going to cut it. (small being less than say 75 gallons). Keep the water shallow provide a sloping land area and make the water part account for at least 2/3 of the enclosure unless you can make a huge one with a really large water feature.
if you have not already, see these good pages:
M Hopsons Asian turtle stuff
ambos at WCT
here's one of Mary Hopson's ambo habitats:
ambo house