I have a very nice, water cooled spindle that runs beautifully. The water is pumped using a small, water feature pump and is more than adequate for the job. However, after a few days, the water in the supply tank takes on a life of its own, growing weird and wonderful cultures. I have tried using a weak bleach solution and it helps but just delays the inevitable growth.

Can anyone suggest an additive or solution to my problem?

Many thanks,

Mike