Answer
Jun 12, 2026 - 02:30 PM
If algae is going back into the pool while vacuuming, it usually means the debris is not being properly captured by the filter system. This can happen if the cartridge is dirty, clogged, or no longer filtering efficiently and needs to be cleaned or replaced.
For sand or D.E. systems, proper maintenance such as backwashing is required, while cartridge systems need regular cleaning or replacement to maintain strong filtration performance.
It is also recommended to treat the pool with an algaecide to help eliminate the issue at the source, such as Frog Algae Gone for Pools up to 30,000 Gallons:
https://www.thepoolfactory.com/produc...
Always follow the product label instructions for proper application and dosage.
