10" fan from home depot in my sump in the summer only. Days get 100+ all summer and ac at 75 works for me.
On another note. I love Tunze powerheads but am really liking the Jebao ow series powerheads.
I have 2 ow25's in my frag system pushing 2.5 years with no issues.
2 0w40's at 1.5 years in my 120 and just put a new ow10 in my.30 gal fuge.
I also have 2 backups of each model. 1 for the ow10.
For the price and controlabilkty of these they are a real bargain.
The ow25's have been running in pulse mode since I have had them.
I run 3 Tunze in my 120 and 2 ow40's.
I know they get a bad rap from time to time but for a long term Tunze guy they are that good, imo.
I run a Tunze carx, skimmer, 2 return pumps, 2 ato's, and powerheads.
Here are the 0w25's before a good cleaning.