| KH and PH are usually tied together. Dangerously low KH means the PH can (and usually will) swing even if it doesn't crash (go below 7.0) and GH even enters into the equation for purposes of keeping PH under control.
But I really don't want to get into all the details here.
By focusing on the KH alone, you are missing the larger picture. No one item will 'fix' a broken system in the same way that increasing filter throughput 'fixes' a pond that is close to PH crash because of a lack of KH. A KH of about 40-60 is typical for many japanese hobbyists. They recommending aren't dumping chemicals into the pond to help the jump filters they use, they instead focus on proper stocking and regular water changes (even flow-through systems).
Even my own KH sticks around 40-60 with almost no GH. I must augment my GH because of my stocking density and the PH swings that occur if I do not. But it really has nothing to do with the bead filter -- it works just fine with my system that also includes a shower filter. My smaller pond uses a cloverleaf and a small shower. Both run low KH because of my tap water although the smaller pond is buffered perfectly well with water changes and oyster shells.
Bottom line -- if the KH of your pond water is the difference between seeing ammonia/nitrites or not then you need to reduce stocking/feeding or increase filtration. |