in the direction of arrow a is swirled inside the housing to promote more even electrode wear and cause any gases produced to be swept away in operation the periodic voltage inverter 12 provides the output signal to the regulator and amplifier 14 the appropriate led 1 or 2 lighting dependent on the polarity of the signal the potentiometer vr1 is set to provide a desired potential difference up to about 34v between electrodes e1 and e2 monitored by the meter the meter also indicates the polarity reversals the potential difference between electrodes e1 and e2 controls the electrolytic rate of the flow cell 16 i e the rate at which ions enter into solution copper and silver ions are thus passed into solution where a proportion floculate and are caught by the filter media removing and killing bacteria and algae and other micro organisms although the size of individual bacteria may vary from 1 3 microns and the filter effect of sand from 10 20 microns dependent on the filter 39 s maturity the effect of bacteria and algae absorbing electrically charged ions of copper and silver produces an electrostatic reaction resulting in charged bacteria and algae clinging together to produce a large filterable mass which is held in the filter media any organisms surviving this process are killed or prevent from proliferating until the next cycle through the unit by passage into water of charged copper and silver ions furthermore the water in the pool or reservoir is maintained at the correct ion level by continuous recycling and regularly monitoring of the ion content by poolside testing this process thus provides a constant regulated and stable source of.