I originally posted this in another thread here but it really belongs in its own thread (so as not to hijack the other one). [EDIT] I finally found some scientific literature that backs up the Nature2 "low chlorine recipe" that uses Nature2 silver ions with MPS here. The following was written before I found such scientific literature. [END-EDIT] This is in response to the Nature2 instructions for low chlorine that are basically daily (or every spa use) addition of non-chlorine shock (MPS) a