What Kind Of Damage Does Low Ch Do?

[njmurvin]

After decon, refill and balance, I checked my CH. My K2106 test kit does a poor job of testing this. I have found other threads on the topic. It is very hard to discern the color changes. Anyway, based on the best I can do with the test, I would say that my CH is very low (30-50). I understand that this can cause foaming but I don't get any foaming. What other problems does low CH cause? Because it's not foaming, my tendency is to let it go. But not if it's damaging any internal parts.

[chem geek]

It will tend to dissolve calcium carbonate from plaster and grout surfaces and from the gelcoat in fibrerglass when calcium carbonate is present there. For an acrylic spa, there is no need for calcium. It is low pH that is the worst for metal corrosion. The idea of trying to produce a calcium carbonate thin scale layer to protect metal surfaces is controversial at best (see this link).