When seeking a hair free, allergy free pet, most turn to the aquarium type. These varieties are great pets to have as they take up only the space you have created for them. Question is - have you considered the care and treatment required for these animals?
Take for example the Red Ear Sliders. These little guys are fast, both on land and in the water. They can become quite the little escape artists if they are able to reach the top of their tank while basking in the light. Don't fret though, they generally stay to the wall or baseboards so it's just a matter of finding which direction they went and how far they travelled.
You will need to upgrade or purchase a very large tank to start with these guys. The suggested size is 40 ltr (10gallons) for every 2.5 cm (1 inch) of the turtles shells. And this is for EACH turtle. They can become cannibalistic if there is insufficient space.
Do not use decorative gravel in the tank! They may eat it and this will cause serious digestive problems. 20 grit sand is a usable alternative, but personally I have found it much easier to clean and maintain the tank and filter if you use nothing at all.
Turtles require high water quality and even with high end filters, frequent water changes are necessary. The more turtles you have in the tank, the more often this must be done. In my experience with having 3 of them, once a week for water changes and once a month for a proper tank cleaning is ideal.
The water must be kept at 78 degrees. Room temperature water creates a risk to the turtles as this can cause them to grow and form with disfigurements and may cause respiratory issues.
Using aquarium-grade salt for fresh water creatures will help eliminate the spread of disease and provides minerals that are missing from tap water.
The first 2 years are crucial as most improperly kept will die. After this time frame, they live up to 30 years. So getting these reptiles as pets are more of a commitment then most people realize. Mine lived up to their mid 20's and I still have one!
A basking area is very important, even tho they are aquatic creatures, they surface to bask, which aids in their shedding. Use an ultraviolet B light freely suspended above the basking area. Glass or plastic between the bulb and the basking area limits the UVB light coming into the tank.
Since these turtles are omnivores they enjoy a variety of plant and animal diet. In the young years they are more carnivores for the protein to grow, I always found they enjoyed the live feed, fish being their fav. Be careful using shrimp as a feed in the first year as they can have issues of chocking causing lung punctures. Later in life, they become more herbivore and it is always good to keep changing their food.
Mine have been on pellets to live fish, worms, and koi food for added nutrients and once and a while they would get a treat of tomatoes or cucumbers. But, if you're looking for something a bit more manageable, I'd recommend Mazuri Fresh Water Turtle Food!
Take care with bringing the pets out of their tank, though they love to roam and explore, there is a very high risk of salmonella, even with constant cleanings and fresh water. Children must be taught to wash their hands properly and immediately after coming in contact with the turtles or their water. If letting them out for play time, keep other house hold pets away as it can be very dangerous to their health. I always used vinegar to clean the floors after play time.
Treat these animals with the care and the respect they deserve, and they will be a great life-long pet for you and your family!