Been SLAMing for two weeks... water still isn't clear

[Fndr70]

I've been SLAMing for two weeks and the water still isn't clear. Don't get me wrong, it's improving, but this is the third year i've had this pool and it's never taken this long.

Relevant details
- My CYA is 35
- My PH is 7.4
- My TA is 60
- I have a brand new sand filter - https://www.amazon.com/gp/product/B07FHHV9YP/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

The day that I started SLAMing, I tested my CYA and found it to be 0. Anxious to get started, I just dumped two gallons of liquid chlorine in the pool and ordered some cYA from amazon. Overnight the pool went from the murky black color where I couldn't even see the. bottom, to cloudy light blue. But it seems stuck there. I know sand filters take a while to filter out the dead algae, and I suspect it's just this because I have to backwash almost every day in order to get the pressure back in the pump, but two weeks?

 

[ajw22]

Your CYA is 40. We always round up. That makes your SLAM FC 16. Is that what you are using?

What is your CC?

How often are you checking your FC?

Are you brushing the pool daily?

Have you checked for hidden algae around your ladder or anything else in the pool?

 

[Fndr70]

I was using 14 for the slam cc. I can round up to use 16.
I check FC 3-4 times a day but always first thing in the morning and at bed time when it’s dark. i try to brush once a day but not always.

There’s nothing in the pool.

thanks for the reply. I’m leaving for a week in 10 days and I’m getting worried I won’t be done by then. I’m getting a house sitter who I can ask to skim the pool and add a little chlorine each day but I can’t expect her to be testing levels lol

 

[ajw22]

Being 2 ppm low with the SLAM FC can slow the process down. Better to be high then low.

While you are gone can the house sitter add a measured amount of liquid chlorine? If so have her add the amounts you added the day or two before for the 10 days you are out. The chlorine demand should not increase and if it decreases your FC will be high when you return.

Can your filter go 10 days without a backwash?

 

[wireform]

You need to keep the slam at full FC level otherwise it won't work. Your filter is most of the set back you're experiencing. They have it rated to work but sand filters take the longest to complete a slam let alone a undersized one.

 

[IceShadow]

What was your previous filter, before the sand filter?

 

[Fndr70]

What was your previous filter, before the sand filter?

Sand filter

 

[Fndr70]

You need to keep the slam at full FC level otherwise it won't work. Your filter is most of the set back you're experiencing. They have it rated to work but sand filters take the longest to complete a slam let alone a undersized one.

With the frequency I test, it typically doesn't drift more than 1 or 2 ppm below the SLAM level.

 

[Fndr70]

Being 2 ppm low with the SLAM FC can slow the process down. Better to be high then low.

While you are gone can the house sitter add a measured amount of liquid chlorine? If so have her add the amounts you added the day or two before for the 10 days you are out. The chlorine demand should not increase and if it decreases your FC will be high when you return.

Can your filter go 10 days without a backwash?

Yeah that's what I was planning or doing - it'll probably end up being 2cups in the morning and 2 at night.

I'll be gone 7, not 10 days. I'm leaving in 10 days... the phrasing was confusing lol. The filter probably can't go that long without a backwash unless the water is crystal clear by then. I was thinking of just putting it on a 4-6 hour timer by then.