Hi Rafael. Air stones are great. I have 2 long air stones in my 125. Micro bubbles are very tiny and can cover the gill plate when you use tap during water changes. At least that’s my understanding and why I age the water in my discus tank. With my angel tank I stuff my python with a piece of filter foam to catch any micro bubbles. Some experienced keepers here taught me this trick and do it with their discus too.