Film/bacteria buildup in Autopot system with Canna nutrients?

Ive never used autopots but my buddy did. He is like a scientist grower im a famer but this is his comment. "My water always had a dusty layer kinda look. Depending on your chemical brand you need to mix in a certain order or it could crash your nutrients out and should be mixed in its specific order according to manufacturers recommendations" He didnt want to give specifics on the brand withought looking things up and it would be my speculation it because the chemicals will bind with each other and possibly stuff already in your water then changing the composition of your water. Side note my wife is a hairdresser and she tells stories about certain types of water can layer things in your hair causing color applications or bleaching agents to do weird chemical reactions and turning out odd. Sounds like you got some reading to do,

within an hour? that's from the fertilizer so i'd assume it's okay. I don't think potable water (before mixing nutes) can form a biofilm that fast even in an incubator and having some hobos spit in it. clean bucket to start? "clean enough" - talking about gardening and not a surgical procedure. any rez that holds water for more than a short period of time needs some sort of agitation/oxygenation. bubbles are less effective than a powerhead, but you probably don't need a powerhead unless you are up near 50-100gallon-sized tank. I use a 1600gph powerhead in my 55-gal rez. Keeps it oxygenated and swirling. these are also called 'wavemakers' for aquariums. Fewer watts than an air pump, quieter, better oxygenation, and better agitation for keeping it mixed. Using "bubbles" suck by comparison. so, learn to differentiate that fertilizer-caused film and anything that grows in your rez a 2-4 weeks down the line. Depending on water temps, exposure to light and how often you top-off will impact how long before the water gets nasty. Smell is probably an excellent way to differentiate.