Halt 50 and Stain Remover

[IASteve]

The previous owners left some Blue Wave Halt 50 Algaecide and 'Rust and Scale Remover' I put in some cheap algaecide last closing season and it turned my pool returns into foam machines when I started up this season - that lasted several weeks.

Just curious if I should either of them before I close or should I just toss them?

 

[JoyfulNoise]

The only algaecide TFP ever recommends is polyquat-60. It will not cause any foaming. All the other cheap ones do because they are made from simpler linear quat chemistries.