Advice on reactions with copper sulphate and aluminium in swimming pool

I have a swimming pool in Portugal with a heating system of aluminium (good heat conductor) tubes, painted black and a small circulation pump. The sun shines, the pool gets warm, cost is minimal and it works well.


As the pool is private, I use a minimal level of chlorination and therefore I use a small amount of copper sulphate (<1 ppm) to control algae growth.


I notice that the heating circuit inlet pipe to the pool leaves white crystals on the floor of the pool.


Question - am I correct in thinking that the copper sulphate is reacting with the aluminium tubes, resulting in a copper coating on the inside of the tubes (not that I can see inside) and aluminium sulphate crystals appearing in the pool?


I understand that aluminium sulphate is essentially 'flocculant' and is not particularly hazardous: certainly the pool stays very clear.


Advice would be much appreciated, many thanks


