hello how often do i have to make water changes and what percentage ? i have two axolotls , a filter for 150 gallons some fake plants and hides and an airstone plus the tank is 112 liters thanks
If you have a 112 liter tank (30 gallons) then the 150 gallon filter is too powerful. It will likely create a heavy water flow and cause a lot of stress to your Axolotl.
Good practice would be around 20-25% water change every week, assuming you already have a stable cycle.