How to Clean Black Algae From a Hot Tub

Black algae is not your everyday garden variety algae. It is, instead, a plant that will resist every chemical attack thrown against it, thanks to a hardened exoskeleton over its vulnerable bits. When this shows up in your hot tub, there is only one method of eradication: You're going to have to climb in and physically tear away that exoskeleton, and then shock treat your hot tub to kill the thing completely. However, this may not be nearly as epic a battle as it sounds.

Wire brush
Shock mixture
Bucket
Metallic algaecide

Instructions

- 1
  Climb into the hot tub and scrub every visible piece of black algae with your wire brush. Continue scrubbing until you have torn away the hard outer shell.
- 2
  Fill your bucket with water from the hot tub. Pour in the shock mix using the formula of 1 pound for every 10,000 gallons of water. Adjust the mixture accordingly if you have less water in your hot tub.
- 3
  Pour the shock mixture into the hot tub and turn on the filter to circulate the chemicals.
- 4
  Let the hot tub sit overnight. Brush the walls down again at least twice the next day. Add the metallic algaecide to the hot tub after the second brushing.
- 5
  Brush the hot tub once a day for the next four days. Add another shock treatment to the hot tub at the end of the sixth day.
- 6
  Brush the hot tub for three more days. Add one more dose of algaecide to the water. This should be sufficient to eradicate the black algae.

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