Red stabil isn't worth the bottle it comes in, quit using that stinky crap years ago. I use the Marine Stabil (blue) and it's expensive, in all my e-gas powered equipment plus a but of sea foam in every gas can full without fail.
In my diesel's it's always Powerservice and a biocide. I learned the hard and expensive way about algae years ago and I NEVER use
B20, That stuff is an algae magnet.
I don't see how people refine fryer grease and use that for fuel, I'd think that crap would really grow algae.