I was talking to someone the other day about tank cleaning and they refered to the fact that there care sheet from petco said to change the water 75% - 100% of the water each week. I am only doing 50% as a lot of others seem to do, how often should I change the water and how much? and should there be 100% changes
The eternal question. How often and how much you change the water depends on how fast it gets dirty. Do you have a water quality test kit? A good one is the Master Freshwater Test kit from Aquarium Pharmeceuticals. Follow the directions for taking the tests and reading the results.
How often you need to change the water is different for different situations. Some people do need to change the water 100% every week or even more often. This is necessary when the filter is weak and the tank small relative to the size of the turtles. Other people can go a whole lot longer and do only partial changes. This is the case when the filter is very good and the tank size is large relative to the size of the turtle.
You can tell how often you need to change the water by the readings you get from the water tests.
Foc 21 – Mama S has it about covered. A lot has to do with sizes. How large if your turtles? How large is your tank? How many gallons of water are in your tank? How large is your filter/pump (gph)? How much do you feed them? What is your lighting situation? How large is you heater? How often do you do your ammonia, nitrite and nitrate test?