Cannot get my water completely clear. Need guidance!

[jwood1298]

Hi All,

First post after many, many hours of reading and learning from your knowledge. This website is fantastic, I wish a similar resource existed for many other areas of life!

I am at a loss for how to get my pool completely clear. This is the third season I've been a pool owner, each year I feel more prepared than the last but this year I've had two episodes of algae blooms that I can't quite seem to kick.

Pool Details:

• ~35,000 gal free form gunite
• Hayward Tristar 900VSP 1.85 HP pump
  • 12 hrs (Night) @ 100%
  • 12 hrs (Day) @ 65%
    • Manually over-riding to run @ 100% 24/7
• 300 lb Hayward sand filter
• In-line chlorinator
• Dolphin S200 cleaner

I primarily use liquid chlorine. I find the chlorinator provides stability in FC if I travel for a few days, and adds enough stabilizer to the pool throughout the year.

After the first round of algae, I performed a deep clean on the sand in my filter (worked amazing btw). Sand was replaced in 2020 when I moved into the house.

Chemistry (currently in SLAM):

• FC 14ppm
• pH 7.6
• TA 80
• CH 190 (a little low here)
• CYA 30

Problem and actions taken:

Currently in the second SLAM trying to beat this algae. I am diligent about testing my pool and I thought I had maintained enough FC to sanitize, but this algae continues to resurface. When I start the SLAM the water is very green, over time the appearance improves but does not completely get clear. Today is day 4, had a FC loss of 2 ppm over night (13-11). How long should I expect this to take? Dolphin is running ~ 6 hrs per day, I brush twice daily. Brushing does not yield any visible algae. FWIW, the pressure in my sand filter seems to decrease over time rather than increase. Backwashing every 3rd day currently.

Thanks!

 

[Texas Splash]

How long should I expect this to take?

It varies for each pool and scenario. Can you post a pic of the water? Four days is still a bit young for a SLAM Process, especially if the water was really bad. Remember that once it's safe to get in the water, you'll need to check behind the light is if has a hollow niche, and may need to check under the drain cover(s). You don't need to run the pump @ 100% rpms. Simply running about 1,400 rpm or so should be plenty. You just need to keep the water moving.

 

[Texas Splash]

Oh, and welcome to TFP! Pool Care Basics

 

[Flying Tivo]

Also look behind the weir door of the skimmer, the foam tends to get hidden algae.