SLAMing for almost a week confused by OCLT results

[blackgito]

Hi, new forum member but reading as much as I can of the great articles and threads here! On to my issues...

A few weeks back my 15' Intex AG pool developed cloudy water and green algae. I figured it was from too low CYA levels and a lapse in FC. I've since started to SLAM just under a week ago, and while the pool remains crystal clear after a few days, I'm confused if I'm making any progress at all. Before I started I raised my CYA to 25-30 (now closer to 40) and then began the SLAM.

Here's what I'm seeing so far:

Date & Time	FC
2019-06-16 @ 10:28 PM	16.5
2019-06-17 @ 07:44 AM	11.5
2019-06-17 @ 10:24 PM	16.0
2019-06-18 @ 07:41 AM	9.5
2019-06-19 @ 12:05 AM	16.5
2019-06-19 @ 05:59 AM	12.0
2019-06-19 @ 10:33 PM	12.5
2019-06-20 @ 08:25 AM	11.5
2019-06-20 @ 09:53 PM	15.5
2019-06-21 @ 08:00 AM	11.0

I've removed the ladder and solar cover since starting and checked them for algae (didn't find anything green) though they also remain out of the pool for now. I've also checked behind the inlet and returns and cleaned them. The pool is free of anything else and I've brushed and vacuumed daily. Checked under the vinyl seams for anything living, but again nothing found. With the exception of 6/19 my OCLT has always been >4ppm. Is this typical? I feel like I'm missing something or testing incorrectly.

Thanks!

 

[Jezza]

Welcome to the forum.

How often are you retesting for FC and raising your FC to a SLAM level?

 

[blackgito]

At a minimum I've tested and raised levels 3 times per day a few days (morning, late afternoon, late evening). I then wait at least 30 mins after the last addition to check FC level at the end of the day. Pump has been running 24/7 since I started as well.

There have been 2 days where I was able to test and raise every 1-2 hours but I haven't been able to do that every day sadly

 

[Richard320]

Well, you've done everything right.

That leaves it with something still in the water --- like maybe inside the filter where you can't see it -- or test error. And test error could be a dirty sample bottle or test cylinder.

Now I'm out of ideas.

 

[blackgito]

Oh boy!

My latest OCLT results again show another 4ppm loss

I sort of suspect the filter and I tried a sand deep cleaning one day. The following day the OCLT result was 1ppm. Unfortunately the water running out of the top of the sand filter never cleared (it was cloudy) before I ran out of time for the day and had to put it all back together. Is there something I can do to the filter to try rule this out? Maybe I can try a longer cleaning routine today.

I should mention I’ve also backwashed twice since starting the SLAM. I’m not really seeing any movement in my pressure gauge though