I would give the store a call today. Did you purchase the exact food it was eating in the store? Did they have a heater and heat lamp on their tank? The goal is to duplicate the way they were in the pet store, or best how they would live in the wild, basking in the sun. You should get the biggest aquarium you can, yes the goal is to get to 75+ but your budget and space might not allow for that right now. It does not have to be overly deep. The more horizontal distance/space the better. They need water to swim in, a dry place to crawl out onto (floating turtle ramp $ or a solid pile of rocks) and love to bask in the "sun" or heat. If they don't have a heat source or lamp there bodies slow down, their body temperature goes down in winter. ie hibernation. We keep them under heat lamps to force them to stay in "summer". If the heat in the room it is in goes lower at night and it does not have its own lamp then it will be affected by it. Make sense?
Your first task I think is to get a heat source over him. a goose neck lamp if you have one. Be careful how it sits, can't fall into the water, I don't know your set up. I hope it's not a little turtle tray 10 inches round, do they still sell those?... he'll definately need more room fast. You can get special bulbs for reptiles that provide heat, with UVA and UVB etc. I don't know what they need, talk to the store! But a basic light bulb, the old style, not the spiral ones, provides heat but it won't be dark like night time. There are bulbs that give heat, infrared, without the excessive brightness. He needs heat ongoing but he also needs night and day just like we do. We all have an internal clock in us. Also while setting up that lamp/heat source put your hand at "turtle level" to see how warm that source is... you don't want it to be too hot either. Set it so that he can move into the warm spot or move away from the warm spot, he needs to be able to get away from the heat if he gets too hot also. Get a thermometer for your tank so that you can know the temperature of his water ongoing, you can check it daily, to maintain consistancy of temperature. Get a little calender book to keep track of what you have done each day. It's hard to remember what you have done on what day. The ideal set up has a good swim area with a filter in it, and small fish for it to catch, feeder baby guppies, goldfish will likely be too big but a couple will make his "world" more realistic. But the fish need water quality too to live, it's all a balance. read lots to find out what they need.
So get the biggest aquarium you can, you can place it on a dresser, you won't necessarily need a stand or glass top, but if you have cats you might want to get a terrarium top for it. That's a metal screen top that fits around the top edge, purchase the exact dimensions of the tank you buy. The store will help you choose the right one.
Hope this helps, keep us posted! Good luck.
Last edited by SeaHorse; 12-29-2010 at 07:01 AM.