78-80 degrees?

I have preset heaters in my tanks to 78f, but the water fluctuates slightly between 78-80f—thankfully doesn’t fluctuate any higher.

I wish I bought ones that were preset or adjustable to slightly cooler temps.

Will my guppies thrive in this water temp? Heaters are expensive so I don’t want to buy any new heaters, just wanted to know if they would be ok or if anyone else has their guppies at this temp.