first off, spend a few hours researching the care of res`s online. a good resource is melissa kaplans site. just google her name to get the addy. she has devoted her life to providing excellent care info on all reptiles, including chameleons. also, anita, who posts here is quite knowledgable about res`s, you might post and ask her for some care info. also, this site has a link for care sheets. you can start your search right here. 3 res`s should not be kept in such a small tank. as far as the one being smaller, it is quite possible that it was sick, this is true. that is why anytime you bring home a new reptile you should take it to an exotics vet and have a fecal exam done to test for parasites as well as a physical examination. the best way to monitor how much a turtle eats is to feed it seperately. there are many other compelling reasons why this is a much better choice than dropping pellets in and hoping they all eat enough. one reason would be that it keeps the tank MUCH cleaner. that should be a good enough reason right there. so, take your turtles and feed them in seperate little containers. with some water in it, res`s need water to eat. make sure it is not too deep for them to come to the surface comfortably too. you should put enough food in there for them to finish in a bout 15 minutes. another thing is that the reason those 2 res`s are starting to look so bulky is because you are feeding them WAY too much protien. thier diet should be mostly veggies. just shred some leafy greens into their tank for them to snack on. the veggies are SO SO inportant because they provide vitamins. the pellets should be fed in the seperate container once a day. also, variety is very important. try tubifex worms, mealworms, teeny tiny feeder fish, egg with the shell crushed in it, and rotate those weekly with pellets. if you offer live food i would bet that your turtles will seem more interested in thier food. it stimulates them to chase down thier food. how boring would it be to eat the exact same thing every day. the chase is FUN for them. also, as far as UVB, get a zoo med flourescent TUBE. if you are using a bulb, you might as well throw it away. its useless. zoo med has proven to be the most reliable source of uvb. keep the tube within 10" of thier basking spot. this goes for your chameleon as well. you can also take them outside for some sun. this is the best source of uvb. basically as far as veggies goes, almost anything is fair game, just no lettuce and no spinach. carrots and anything high in vit A is also very important. your water temps are too cold also. bump up the temp to 80-85. if you do, i guarantee you will notice a HUGE difference in activity and appetite. if they are too cold they cannot digest thier food properly. they are babies and if they are indeed getting sick, they need the extra warmth to boost thier immune system. the basking spot should be about 85-90. one more thing, you mentioned that they are your sons turtles and they stay in his room. i just wanted to mention that all reptiles carry salmonella. salmonella could be fatal if your son were to get it from the reptiles. the tank should be in a place that your son cannot access. and if he does hold the turtles, make sure he washes his hands VERY thoroughly. salmonella is passed in thier stools, so even touching the water or anything that comes in contact with the turtles has the potential to transmit salmonella. get some lysol and bleach and spray the doorknob and anything else you or him touches with "turtle hands." also, i hope that you do not clean the tank in the kitchen! as far as him being sick from october. it is a long time. but reptiles are cold blooded animals and can prolong thier life by staying cooler. if he was the one that was always hiding or if you noticed him sleeping during the day at any time then he was probably sick. animals do not display symptoms of being ill until it is usually too late. in the wild the weak ones get eaten, so to show weakness is to die. that is why you may have never noticed an "ill" turtle. please take your turtles to a qualified vet and have them checked out. if you need a vets name, again melissa kaplans website is a great resource.
meagan