That sound like a good idea, @G-paS. You can get air tubes like some aquariums use. It is a plastic foam of some sort and won’t put any thing into your water. I learned that here 15-16 years ago. 
That sound like a good idea, @G-paS. You can get air tubes like some aquariums use. It is a plastic foam of some sort and won’t put any thing into your water. I learned that here 15-16 years ago.