How often do I backwash?? clearing algae

aesweeps

Well-known member
Jun 9, 2014
76
Charlotte, NC
In process of opening pool, algae was everywhere on day 1, I brushed, backwashed, and got it to shock level. Day 2 and 3 has been a lot better, water is cloudy but no longer green. Brushing everyday, but I only backwashed the one time on day 1. The pressure is good/normal. Should I be backwashing more?? Thanks in advance.
 

LionBiscuits

Member
Dec 21, 2019
18
Florida
Have you used any clarifier or floc? Continuing to backwash/vacuum to waste without ensuring the algae is dead and on the floor is just gonna burn a hole in your pocket and waste water.
I'm not entirely familiar with sand filters yet, I'm still learning as I go. But here's how I recently did it:
  • Removed all debris & ensured all plumbing is good-to-go
  • Clean filter (Mine is a cartridge filter)
  • SLAM, SLAM, SLAM
Again, this could all be entirely nonsense due to the fact that I'm inexperienced with sand filters- just wanted to give my 2 cents on how I managed to turn my radioactive-looking pool into a sparkling, swimmable pool.
 
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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Sweeps, you backwash when the filter pressure increases by 25% from the clean/starting pressure. Usually the psi on the gauge increases quicker in the early part of the SLAM Process, but every pool is different. At TFP, we generally avoid using floc or clarifiers except in some very unusual circumstances,m so I would stay away from those. Just follow the SLAM Process page and maintain the proper FC Slam level as noted on the FC/CYA Chart based on your current CYA.

If you have any other SLAM questions, let us know.
 
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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Sweeps, you might also want to post a full set of water results just so we can confirm you are on track. The SLAM Process works, just be faithful to the process, maintain the proper FC level, and have patience to let the chlorine do it's job. It can take several days, maybe even a week or more. You'll get there. Also consider taking a pic of the pool each day to monitor the water clarity changes. Don't stop the SLAM until you pass all 3 criteria.
 
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aesweeps

Well-known member
Jun 9, 2014
76
Charlotte, NC
Sweeps, you backwash when the filter pressure increases by 25% from the clean/starting pressure. Usually the psi on the gauge increases quicker in the early part of the SLAM Process, but every pool is different. At TFP, we generally avoid using floc or clarifiers except in some very unusual circumstances,m so I would stay away from those. Just follow the SLAM Process page and maintain the proper FC Slam level as noted on the FC/CYA Chart based on your current CYA.

If you have any other SLAM questions, let us know.
THANK YOU SO MUCH!!!