Help for friend's pool - algae?

[jlsmith123]

Pool open (late April) and beginning of season was uneventful as normal. Then toward the end of May the water became cloudy and an unidentifiable ‘scum’ started to form.

They've been working with a pool service company for the past month+ without success.

Pool is ~40,000 gallons, they think it's chlorine. I used my Taylor kit and took measurements a couple days ago which are:

• Chlorine 0
• pH 7.4
• Alkalinity 180
• Calcium Hardness 70
• CYA 0

I think SLAM is needed. A few questions:

• Would you agree w/ SLAM approach? What else would I need to know to determine if it's the best approach?
• If SLAM is best approach, in what order should the fixes me made, as CYA and alkalinity are off balance too?

Thanks for your help!

 

[Jimrahbe]

123,

If you can see algae, then a SLAM is the only option used by TFP...

You want 20 to 30 ppm of CYA no matter what, but you don't want to go over 30 if you can help it until the SLAM is complete.

I doubt the pool company will want to do a SLAM, so your neighbor will need to pick who they want to take care of their pool.. A pool company or TFP...

Thanks,

Jim R.

 

[Jimrahbe]

123,

Another option is to drain and start over...

A 40K pool will take a lot of Liquid Bleach... In a lot of places, water is the cheaper option.

Thanks,

Jim R.

 

[jlsmith123]

123,

If you can see algae, then a SLAM is the only option used by TFP...

You want 20 to 30 ppm of CYA no matter what, but you don't want to go over 30 if you can help it until the SLAM is complete.

I doubt the pool company will want to do a SLAM, so your neighbor will need to pick who they want to take care of their pool.. A pool company or TFP...

Thanks,

Jim R.

Thanks, yes, I understand. What's the reason to not go over 30 CYA until SLAM is complete?

I know SLAM method is labor intensive and a pool company is unlikely to want to do it...we had to do it last year and it was 2x daily measurements and chlorine adjustments for a week. (we take care of own pool...as it's pretty simple with tfp method)

 

[jlsmith123]

123,

Another option is to drain and start over...

A 40K pool will take a lot of Liquid Bleach... In a lot of places, water is the cheaper option.

Thanks,

Jim R.

Oh wow. Never would have thought that just starting over would be cheaper.

We did end up buying way too much bleach for ourselves this season, so have about 20 extra jugs we could give to the cause. But that may go pretty quick.

 

[reggiehammond]

Thanks, yes, I understand. What's the reason to not go over 30 CYA until SLAM is complete?

I know SLAM method is labor intensive and a pool company is unlikely to want to do it...we had to do it last year and it was 2x daily measurements and chlorine adjustments for a week. (we take care of own pool...as it's pretty simple with tfp method)

30 CYA provides the UV protection you need; anything more just requires more FC for the same effect. You can SLAM at higher CYA’s at greater expense, but there’s no benefit.

In the first 2 days or so of SLAM, more frequent adjustments (4-5x day) can help speed it up.