The insides of my 5-6 year old Pentair MiniMax NT gas heater just rusted out. I re-plumbed to skip the heater so we can still use the pool, but I curious about what would be the major cause for this - having a SWG or having pH running a little high much of the time? pH has been a little bit of a battle for me. I haven't had a chance this week to collect/post my pool chemistry, but even if pH were high for the last month or so, would that be enough time to rust through or is this a longer term problem?

I'll probably ask for heater recommendations at some time in the future but if there is a better time to get one (fall vs spring), I'd appreciate knowing that too

22k gallon IG, SWG

Thanks
Charlie