The Un-Filters 401

Chapter 8

The Role of Circulation, pH and Alkalinity

Once full ionization has been achieved, good circulation plays a critical role in distributing the ions, and this point has been prominently ignored in some quarters.  You may have heard Ionizers can simply be dropped into the water feature or in the skimmer near the pump, and they will work perfectly well.  This is ABSOLUTELY FALSE.  Unless there’s a stronger force, powerful molecular attraction will just snap the ions across the small gap from one electrode across to the other, rapidly consuming the electrodes without ever affecting the pond. It’s absolutely essential to plumb the Ionizer so that a strong flow of water passes between the electrodes, sweeping the ions away from the opposite pole that they would otherwise immediately bond to. Circulation within the pond is equally critical. If, as is typical, there’s only one spot along the perimeter that ions enter the pond, say, where the stream pours into the pond, and the pond is long or poorly circulated, ions may never reach areas that need control. Where the ions don’t physically reach the algae, they cannot control it. Better circulation or additional Ionizers may be necessary.  The same is true for larger ponds, where multiple units may be necessary to maintain an appropriate level of ionization.

Both pH and Carbonate Hardness also play significant roles in algae control through ionization.  The pH affects which type of copper salt will form, and acidic waters with low pH form compounds that are more toxic to other organisms, while the copper compounds that form in alkaline waters are less damaging to algae cell metabolism.  Care should be taken to keep the water as neutral, pH as close to 7.0, as possible; where water is very alkaline, ionizers can be harder to use and less effective.  The same goes for total carbonate hardness (KOH); too much (over 250ppm) and the electrodes tend to scale over, reducing ionization effectiveness, too little (under 80ppm) and the pond is liable to experience more extreme daily pH swings towards acid conditions that render the ions more toxic to organisms other than algae.  The optimal level of KOH is around 100-120 ppm.  Get a test kit that measures both, for the best possible outcome with the Ionizer. Don’t worry about testing the levels of Silver and Zinc if your Ionizer uses electrodes made from Copper, Silver and Zinc. The proportions of the three metals in the electrodes are set so the proper amount of Copper will assure the correct amounts of the other two metals as well.