Zebra Danios at 78 degrees F?

I'm starting a 55 gallon almost finished cycling and wanted zebras, tiger barbs, red tail black shark, and bristlenose pleco. My question is I've seen they prefer up to 75 degrees. I was planning on 78. Would this be a problem

 

What does it do if it's 75 degrees?

 

I personally wouldn’t go higher than 75 with them.

 

In my research I've seen their temp range is 68-75 degrees and my tank will not be this cool. Don't know how to keep it at 75 without using a heater and keeping my a.c. at that temp

 

I personally wouldn’t go higher than 75 with them.

Ok thanks, patience pays off again. May have to get something instead of zebras