outdoors is much different then indoors....the ground temp stays fairly stable during growing season. i know they grow at lower then recommended temps. but yes it does affect them negatively. google it.
my ro unit needed a break in period so to speak...it started around 50ppm and after about 50 gallons it dropped to 10-15ppm. the manufacturer said i would need to run around 100 gallons for it to break in.
i read where 2 guy did a burn that got out of control and were sentenced to jail. they did their time n were released. then the judge said it wasn't long enough n sent em back to jail......wtf!!!