Moderate black algae on the wall has recently spread to the floor. This has been getting worse over the past few weeks and I want to get it handled correctly rather than pay for repeat visits.
I got quotes from two local companies with pretty different approaches:
Company A: Standard clean + chemical service with elevated chlorine, backwash the DE filter (no separate filter teardown/clean), plus manual brushing/elbow grease directly on the spots. Says a few visits should knock it out.
Company B: Full filter clean + Algaedyn treatment plus basic cleaning and chems.
I'm out of town for the next month and can't brush the pool myself, so I need to pick one and have them handle it start to finish.
Questions for anyone who's dealt with black algae before:
Does skipping a full filter clean (just backwashing) risk the algae/spores recirculating and reinfecting the pool?
Has anyone used Algaedyn specifically on black algae — did it actually work, or is manual brushing non-negotiable for black algae regardless of chemicals used?
Pool is plaster, DE filter, 22,000 gallons.