Black Algae in Jetted Tub

I am getting ready to sell my house and I have a Jetted bathtub that we never use. It has algae build up in the jet pipes and spits out black stuff. I have to sell my house now and our buyer want the tub clean and free of algae. What is the best chemical and means of cleaning it?

For a quick cure Jet Leisure Time Jet Clean and OZ shock. Fill the spa with hot water and use 3 tablets of the OZ, let the tub run for a bout 15 minutes. This will kill the algae. Drain the tub and use about 1-2 cap full (s) of the jet clean. Let the tub run for 30 minutes then turn it off and let sit for another 30 minutes. Turn the tub back on for 30 minutes then drain and clean it. You can refill and repeat this until all of the algae is gone. (Use small amount of the jet clean, it will bubble up like a bubble bath and may overflow.) You can purchase both from Easy Times Hot Tubs web site. This is also a good maintenance procedure for the future owners to do to keep the tub free of bacteria and algae.