Hello all, I tried searching for this, but can't find anything on it. We started the TF system last year and I got a lot of flack from one of my dh's friends saying that you cannot use baking soda with a cartridge filter. We had absolutely no issues with it. Now we are looking into getting a gas heater and he is saying that you most definitely cannot use baking soda with a gas heater. Is there any truth or proof to this? I don't want to mess anything up! Thank you!