I recently found out about air stones that you can use in your tank that whilst not as effective as something such as a filter, can work towards keeping your water clean and also helping with the oxygen in the water as well.
I have never had an airstone in my tank before but I do wonder if others do have one and whether they feel they are beneficial to their tank.
Do you have an air stone and is it something you would recommend to someone else with a tank?
