Waste returns to pool

[Frustrated]

I recently opened my pool for the year. Last year when I closed it there was a lot of algae in it. I put new sand in the filter and when I vacuum the algae returns almost immediately to the pool. I think something is wrong in the control housing of my filter where I shift from filter,backwash, rinse Etc. Can you tell me what to check for in the housing.Thanks
BTW, it is a Astrapool Millennium Series 2000.

[Guest]

How long do you backwash and how long do you put it on rinse?

Not sure if it's the right way but I usually put it on backwash and let it drain for about a minute or a bit longer after I see the waste water go from cloudy to clear. I then put it on rinse for about another minute. I then switch back to filter. I sometimes see a slight amount of waste, a slight cloudy stream, wash back into the pool. That's usually due to not enough time rinsing.

As for algae, the chlorine and algaeside should take care of it as long as you backwash accordingly. Don't expect instant results. It takes time to do the job properly.

[doubled1]

Vacum the algae to waste then add fresh water.Keep chlorine level up to 10ppm until the algae is dead.