Can you get Algae in a hot tub?

Yes, but it is not that common.

Algae growth in spas is fairly uncommon, unless the spa is outdoors and not used often. To prevent algae growth, maintain proper sanitizer level consistently and circulate the water several hours daily.

If algae is present, add 2 tsp. of Brominating Concentrate per 100 gallons. Circulate several hours. Clean the filter after treatment. More than one application may be necessary.