Feeding
The best way of feeding that I have found is by placing the food on the turtle dock, this way I can monitor how much food is left, and unwanted bits of food are not left in the water to rot and can be easily removed if necessary. Turtles are unable to eat out of the water, they drag their food in the water and eat there. With amounts, terrapins should eat about the size of their head (hollow) in protein a day until they are over 6 months, then it should be every other day. They should have greens available to them all the time as they would in the wild. Its best to only feed 2 or 3 pellets a day per terrapin.
I have found that they seem to enjoy pretty much everything, at the shop I was told it was only necessary to feed them on the premixed dried shrimps and tubifex and sometimes to treat them with dried bloodworm but it can’t be interesting for them.
Terrapins enjoy all sorts of salad, vegetables, fish foods, algae tablets and they especially love earthworms which you can buy on many reptile food sites. Mine have a varied diet including reptomin sticks, king british terrapin food, bloodworm, algae tablets, ant eggs, earthworms and greens. Greens come best in the form of aquarium plants, most of these are ok but the favourite seems to be duckweed. You could buy a few plants and then grow them yourself in a seperate tank. They also enjoy salad greens, nothing with a high water content though, such as iceburg lettace. Just remember to throughly rinse anything that has been shop bought for human consumption. They also like dandilion leaves, but again, wild grown would really need a good rinse. Other foods include crickets, worms, pond snails and locusts, these are not always best for hatchlings but adolescents will love them, plus you can 'gut-load' them which means feeding them on high calcium foods so when your terrapin eats them, they get all the calcium as well.
It is important to remember that a lack of calcium in the diet can cause serious problems for the turtles. The calcium hardens their shells and without this intake they can sometimes develop a condition known as soft shell. So even if you are trying to liven their diet up remember to still include those vital bits of snails shrimps, cuttlefish or even just calcium tablets if you can get them to eat them. Although I say they will eat practically anything just be careful because their digestive system can not handle the same foods we can, so tit bits and leftovers are a big no!
Many websites promote feeder fish, (livestock intended for food) this however, is against the law in the UK and any decent pet shop owners will not give you them if they know your intentions, it also poses a large risk. Although it may be fun for the turtles, the fish could be carrying diseases or parasites which in effect could kill your beloved pet so I personally don’t think its worth the risk. However. some keepers chose to do this, and often breed their own guppies or other small tropical fish this helps reduce the risk of disease and they can be a little more certain that the fish are safe.
I think the best way is trial and error, you don’t know what they like until they try it, anything they don’t like will be left behind and you will know.
It may be interesting for you to know that males and females often prefer different diets, this is a good way to try and determine sex before it is physically visible. Females tend to be more herbivorous and males tend to be more carnivorous but I wouldn’t put money on anything when they are babies, just something to look out for. With a little patience and trust you can soon have your turtles taking food from your hands.