I have a new AG 27' round pool that is about 6 weeks old now. The water is very clear, but my water balance is a little corrosive:
temp: 85 deg F
I've been keeping the FC above 3.0, and the water has been sparkling clear. We have a solar cover that we keep on almost all the time and have not yet used the gas heater. In fact, the gas line to the heater is still not complete (although the 140-foot trench is complete). The 2-speed 1.5 HP pump has only run on low speed since the electrical service is just now near completion - it's running on a long extension cord now which has too much voltage drop for the high speed to run. So I've never vacuumed and other than some sand, the pool still looks great.
For my initial pool fill, I had city water trucked in, which put most of these numbers where they are without adjustment. I just added my first top-off from my softened well water, and I have TA about 280 and CH=0 in that softened water. Unsoftened has iron in it, and is not an option at this time (I may create a filter adaptor that I can attach to my hose to remove the rust, but that's a low priority for now).
The water flow goes from my filter through the heater and back into the pool. Since my water balance is slightly corrosive, I am considering taking the heater out of the water loop for the hotter months, or until I get the water balanced. Or should I add some CH and raise my pH and keep the heater in the loop? I just started an attempt to aerate with the return eyeball pointed up and keeping the cover off during the day, and the pH raised from 7.2 to 7.3 in one day. Is there any other reason to be worried about water balance besides the heater (like the pump)? I kind of like having the pH on the lower side, and it appears that the solar cover usage is keeping the need for bleach low and the temps high.
Oh, the heater is a Rheem 206, which has the plastic headers and copper tubes between them.