Wood Stove heater

Question 1: What additional chemical issues might I have to worry about due to the fact that I heat my pool to 98-101 in the winter with a wood stove that has a stainless steel jacket through which the pool water circulates? The plumbing is PVC except for a few feet of iron pipes and fittings in the back of the heater.

As per my signature line below, I have an in-ground, 15 year old, 20,000 fiberglass pool that uses a Nature 2 cartridge to sanitize the water and keep the algae down. For years I had no problems. Then 2 years ago the hot winter water turned dark - Local pool stores couldn't find anything in the water... OK it eventually cleared up, so it is not my current question. My question is the preventative, educational one posed above.