they say red slime is a type of bacteria, not algae.
should find out the cause of it as opposed to metting out temp measures.
just something to ponder over that might help.
Maybe check your water source - use DI water? phosphate, nitrate level?
your tank current phosphate , nitrate level?
feed heavily? both corals and fishes - cut down amount and frequency?
shorten photo period?
do more frequent WC?
new tank sydnrome? - newer tanks have this issue but should stablise 3 - 6 months later.
sufficent flow in the tank?