red foot wont eat and has diarrhea

I have 2 6 inch plus red foots I got a month ago, the ones fine and eats everything, the other has the runs now and wont eat. I been weighting them and a week ago the smaller one was 650 grams and a week later yesterday I weight them again and shes at 696 grams but hasn't eaten and she has had the runs a few times I been soaking her everyday for 20 mins with 90 degree water and put new water in when it drops past 85 I have a top model reytek temp gun, the warm side of cage is 90-92 and cool side is 78-80 and I mist them once or twice a day and cool side is the dryer side too. I feed them spinach and kale sparingly once a week, spring mix, butter worm once a week and earth worm, and pumpkin every 10 days and more now to get her to eat it with her having the runs to help stop it, papaya, strawberries, banana once in a great while every 2 weeks and only a small bit, yellow squash, zucchini, mango, hibiscus flowers and leaves, Christmas cactus once in a while, cabbage every other week, collard greens, endive, kiwi, apples, pears, green beans and carrots once a week, hens and chicks, that's all I can remember there might be more. I don't see any worms in the stool and my other 2 torts are fat and happy and eat a lot. There cage is 2ftX4ft with plain top soil 2in and 4in of sphagnum moss, and 2 hides, and 2 black heat lights and a 24in uva/uvb light on for 12 hours every day. The closest vet is 3 hours away and I cant send them sample and cant go that far with my work hours. I tried asking if I could send it in with check but they said no even over night it they still said no to that. So im a stump now I have a sick tort and a sick turtle now. the water turtle has some sort of shell rot I posted on 2 forms now and nothing on that yet. Any help or suggestions will be greatly appreciated. Thanks

The way i see it there are two scenarios here. He could have diarrhea because he's not getting enough fiber in his diet, or he could be truly sick. You can try increasing the heat giving him a basking site with a surface temp of roughly 110 degrees, increase the humidity, and change his light to a powersun by zoomed. This may help him cope but without a vet, he may not get better, so do whatever you can to get him to a vet.