That recommendation is because for a seasonal pool stabilized chlorine is used so the CYA level builds up and you need an algaecide to prevent algae. If you instead use chlorinating liquid or bleach at a fixed CYA level, then you won't need any algaecide, but you need to be diligent about maintaining the FC level for your CYA level.
As for the algaecide, you've got the wrong stuff. It's a common linear quat so will tend to foam and it will break down faster from chlorine. It's less expensive, but you get what you pay for.
