M3 and M5 are not pure methanol but with additives.
Aquamist clearly stated on every system should only use water or 99.9% pure methanol. Any traces of hydrocarbon will be absorbed by all the rubber components in the wetted paths. Those components will swell up, weaken and eventually falls apart.
There are basically a hand full of rubber used in this industry. Viton and EPDM. Viton is designed for hydrocarbon and EPDM for alcohols. Neither is good for for both.
Here is a picture of a diaphragm being used in the wrong environment, namely M5 with small amount of nitromehane added.
