Ok so I switched over too using a smaller python for the winter. But my 50 foot I use for the summer; my dad just found saw it and said there is mold all in it. my father and I cleaned it out. Now should I just use this for removal? and no longer for water entering the tank? or will the mold hurt my fish. please answers are great. or have my dad laugh at me this will be my 3rd 50 foot they are 125 a piece.