I should also add that the new furnace has a much better air filtration and sterilization system, so running it 24/7 will provide “cleaner air”, which may be useful during flu season. We also have a 12 year parts and labour warranty which helps in the event the blower does wear out, but my experience tells me it is the stop and start that does more damage on motors. I would be curious to know what happens with your aquarium ph levels after doing same for a day?
Oh, do you have a uv sterilizer on there? Yes I'll try it and see, my ph goes up to 8.3 as is and I took of my co2 scrubber because I was getting too much precipitation at higher levels, but I am interested to see if it has an impact regardless.