Hm-mmh.

My problem is that I have ZERO personal experience with pink algae (it's not actually algae), and very little information about what might be most effective. Complicating the issue is that it is an opportunistic biofilm community that's going to tend to stick around in cracks and crannies even after it's 'all gone'. So, you not only need to get rid of it, you're going to have to keep getting rid of it.

What do you want to do?

Option #1: I looked at your pool online (Google Maps has a very nice image of it!). Since you've got no steps, you can probably drain to 8" deep in the shallow end, without too much risk. That will give you about a 60% drain, reducing your CYA to ~140 ppm. Then you can refill and treat with high chlorine. You can also go to 60 ppm borates, which may, or may not help but will reduce your pool's susceptibility to true algae.

Option #2:Try chemicals till you find what will work. I suspect the cheap quat algaecide at Sams Club will work . . . if you add enough to make your pool soapy and THEN brush. You'd only be out $30, but your pool will be soapy and probably irritating to eyes for maybe 2 weeks. You could try polyquat which is more expensive, and may not penetrate the biofilm well, though it might help if used at the same time, as the other. You could use ammonium chloride, to produce monochloramine which penetrates biofilms MUCH better than regular chlorine . . . but monochloramine is irritating.


Honestly, if it won't bust your budget, I'd probably try this in your shoes:
  • Do a 50% drain (8" water in the shallowest stpot) and replace => $###?
  • Add 60 ppm borates (19 boxes of 20 mule team, plus maybe 6 gallons of muriatic acid => $100)
  • Add 1 pint of polyquat and brush every 3 days for 2 weeks (3 x $20 => $60)

If that doesn't work . . . you can move on to the foamy quat + monochloramine. But the first 3 steps are all stuff that's generally good for your pool, ANYHOW, so there's no waste. And, none of that will put your pool out of service, except for the time it takes to refill.

One BIG caution: do NOT do this if the ground around your pool is wet! If you're not sure, dig a post hole next to your pool. Let it stand overnight. You can drain to 1 foot ABOVE the highest water level in the hole.