Inactive RES

Question
QUESTION: Hello there,
  I have two Red Eared Sliders. They are both around 1 year old and i still don't really know their sex. They both share a 20 gallon tank equipped with a good filter, water heater, lights, basking areas and all that good stuff. The thing is, though, Yoshi (one of my turtles) is always on the corner and doesn't really come out much. Initially, i though it was because that's where the water heater was but now I'm not too sure. Out of both of my turtles, Yoshi is the biggest and Peach is a bit smaller-same age. Any ideas as to why my RES might like that corner so much?
    Another thing, sometimes i catch both my turtles vibrating their hand in front of each others' faces. Could this be aggression or mating. I ruled out mating because i thought they were too young. I'm not all too sure about the aggression because they always sleep together(kind of hugging each other) in that corner i was telling you about or just hang out there. Well, any insight helps.
         Thanks a bunch,
         Elizabeth

ANSWER: Hi Elizabeth,

If your turtles are a year old, they're probably around 3" or so.  You need a bigger tank.  A 20 gallon tank is really only (barely) adequate for hatchlings.  Turtles need large tanks in order to maintain good water quality, and a pair of mature RES will need a 125-150 gallon size, with corresponding filter (it should have a minimum filtration rate of twice the tank capacity).  You can get by for now with a 60 to 75 gallon tank, but it's easier in the long run to upgrade to the adult size tank.  

Providing a bigger tank will allow for more swimming and basking room, and help to reduce stress in addition to improving the water quality.  It's possible that Peach is more aggressive in competing for basking area and food.  This can often cause the less competitive turtle to hide or become withdrawn/lethargic.  Turtles aren't friendly with each other in the sense that mammals are--sharing basking or sleeping areas may simply be due to those being coveted areas.  

You should also make sure that your UVB bulb is relative new--tube bulbs need to be replaced every six months, and combo bulbs (heat/UVB) should be replaced yearly.  The UVB can degrade pretty quickly past the optimum time.  A varied diet is also important:  animal protein and greens in addition to pellets.

Fluttering can be a mating behavior, but in juveniles it may be territorial or competitive.  This is another reason to increase the tank size, because if the fluttering escalates to biting, you could have a real problem on your hands.  

Below are some links to care information that will give you details on tank size, filtration, etc.  Good luck!

http://www.redearslider.com
http://www.austinsturtlepage.com/Care/caresheet-red_ear_slider.htm
http://www.austinsturtlepage.com/Care/care.htm
http://www.austinsturtlepage.com/Care/waterquality.htm
http://www.austinsturtlepage.com/Articles/filtration.htm
http://www.austinsturtlepage.com/Care/housing.htm  

---------- FOLLOW-UP ----------

QUESTION: Ok thanks. Another quick question: do I increase the amount of food given as they get bigger or give the same?

Answer
RES tend to be real food hogs, and they can become overweight, sometimes so much that they can't pull into their shells.  Gorging is instinctive for them, because in the wild the food supply isn't necessarily stable, so they eat as much as they can when food is plentiful.  Obviously in captivity food scarcity isn't a problem, but they don't know that!  Hatchlings should be fed daily, but after the first six months to a year cut back to every other day feedings of either pellets or animal protein.  You can offer greens daily, but not too much.  A general rule of thumb would be to feed an amount (pellets or animal protein) roughly equivalent to the size of the turtle's head.  Your turtles may beg for more, but don't give in, because at their age you don't want them growing too quickly.  Make sure that each turtle is getting his share of food as well.