RES TEMPS! AND HYGROZYME

Alright, been juggling around with reservoir temps so far I can keep temps in 64, but once the ice runs out it jumps up to about 80. I got a rotation happening now where I can rotate frozen bottles so it's constantly cool, the highest the temps reach when cooling is 69.

Is that adequate having a range from 64-69? 64 mostly happens at night though, grow room temps range in the high 70's. As long as I keep the res chilled grow room temps don't really matter, I mean not insanely hot (like 90's)

Also for Hygrozyme, I've been using it and I have seen nothing but brown algae produced from it; but that was prior to chilling the res. Is it worth trying Hygrozyme since I can manage the temps in the reservoir now? I think the brown algae was the combination of the temp and hygrozyme feeding the algae.

Also will I notice an increase in growth speed, since I now have the res temps dialed in properly?
will Ph be more stable as well?

BTW Res temps before chilling was around 80f