Hello,
I’ve bought an aquarium for my RES. Before it I kept him in a very little vessel. Aquarium dimensions are 20x10x15 inches (13 gallons) and I have filled it with water up to the height of 7 inches (6 gallons). Also we have installed an internal filter (sonpar-wipero TC-700, max. Liter/hours of 390, max. water head of 0.75 meter, power of 6.8 WATT) and put a rock in the aquarium (when he comes to the top of the rock, he is out of the water). I have some questions:
1. Feeding: before that, because we used a little vessel my RES could just stretch his neck and eat the food. But now when we put food on the surface of the water it is very hard for him to catch them. It’s also hard for him to catch foods near the rock because they move. How should I feed him now?
2. Filtration: the filter has a plastic pipe which when is out of the water I think injects air into the water, and makes a powerful stream but when it is in the water stream is less powerful. Also I use foods which are in the form little spherical things and regarding to their size their remains are not absorbed by filter:
Should the filter work all the time or just specific hours? Should the pipe be out or in the water? Should I use less powerful filter? Is it a problem that remained foods are not absorbed by filter?
3. Water change: when my RES lived in a little vessel I changed the water twice a day but obviously I can not do that so frequently now! What is appropriate time period of changing water with the aquarium conditions that I mentioned before?
4. Smell: and at last when I keep my nose close to the water is smells so bad. Is it dangerous for my RES?
My RES size is the size of palm of a matured person (about 4 inches) and it’s more than a year that we have been keeping him.
Excuse me for this long post and thank you for your help.

