SLAM'ing and no improvement

[animous]

Hi,

TLDR; I've been hit with algae and I can't SLAM it out. Help?

In the past few weeks there were a few days of very heavy rain. This, combined with the fact that I let FC drift too low resulted in algae taking over.

I started SLAMing 5-6 days ago. Last year I would get quick results, but this time (first time this year) it's the longest it's ever been with no visible results. I'm stumped.

Since starting SLAM, I vacuum every morning (to filter) with a "dumb" suction side cleaner, then brush walls and floor and backwash. Backwash is always 100% clear. I also brush walls and floor in the evening before adding more liquid bleach. I use the TFP app to calculate chem amounts and log levels. Pump running 24/7.

Jun 19
FC 2.0
pH 7.4
This is when I let the FC drift too low, big mistake. Will shoot for min 5-6 from now on.

Jun 22
CYA 40
Add 600g trichlor
Add 500ml of 29% acid to bring pH down to 7.2
Add 1.5L bleach 10.8%

Jun 23
Add 3L beach 10.8%

Jun 24
FC 12.5
Add 2.2L bleach 10.8%

Jun 26
FC 16, pH 7.4, TA 70, CYA 40, TEMP 72F

Jun 27
FC 12
pH 7.8 (or 7.2?!)
Add 600ml 29% acid. (I forgot that pH readings are affected by 10+ FC)
Add 345g alka+ (because of TA 70, but maybe that was off too because of 10+ FC?)
Add 2.5L bleach 10.8%

Jun 28
Add 2L bleach
Add 400g trichlor
FC 18
Add 1.5L bleach
At this point even though I'm above FC 16, I'm thinking with CYA being ±10, I'm going to add more bleach just in case.
Had some algae film in the skimmer, which was a first ever. (now gone)

Jun 29
FC 25
pH - 8.0 (or in fact 7.2?!)
Maybe I went a little overboard with the bleach. However, it made no difference. This morning is like every other morning: algae all over the floor and walls, and the bottom isn't visible in the deep end.

Questions

• Why isn't FC 16+ yielding any visible results?
• What are my next steps, should I just maintain FC 25 and keep vacuuming in the morning and brushing twice a day?
• Should I add muriatic acid?

The dark side is calling, that algicide is starting to looking mighty tempting. Help and thank you!

 

[animous]

Replying to my own post, but it seems that Pooltec is polyquat60, which is not frowned upon by TFP. So not-so-dark side after all.

And reading through a few other posts, it seems I might be impatient and need to maintain that high FC for days or even weeks! Didn't expect that based on past experience. Looks like I will need to stock up on R-0870 and R-0871!

Any tips still welcome. Thanks!

 

[PoolStored]

Biggest tip: Test and replace FC every hour or two. The more often you do this the faster it will go!

 

[Texas Splash]

For now, focus on two things:
1 - Maintaining the proper FC SLAM level of 16
2 - Inspecting/cleaning every possible location of the pool where water touches.

You can ignore the TA and pH until the SLAM is over. Unless you do a lot of backwashing, the CYA should remain in that 40 range. Follow the SLAM Process page carefully and it will work. No need to scour the internet for quick fixes, or to use algaecides or anything else. The proper amount of chlorine, based on the current CYA, is what you need.

Be sure to inspect closely. If you have a main drain, check under the cover. Any ladder/steps should be removed. If you have a large light with a niche behind it, the light should be removed (power OFF) to clean the niche. Look for any folds in the liner too. You can't be too critical when it comes to inspecting for algae.

 

[animous]

I don't know if it's because I removed the ladder, or because temps have been dropping or just because of time, but there seems to have been some progress overnight. BTW the algae is what many others seem to be getting: it is super easily brushed, and forms a green-yellowish cloud in the water when brushed. I push it all towards the deep end.

@PoolStored thanks for the tip, I will be replacing more frequently!

@Texas Splash There are a few folds in the liner in the shallow end. I had them removed last year, but they came back in Spring (I believe the liner floated up, but that's another rabbit hole). Is it sufficient to give those folds an extra brushing?
I can't access the main drain for now. I removed the ladder. Glad I procrastinated on putting new lights in after the liner was changed; the niches are completely covered by liner so one less element to worry about. Thanks!

 

[Texas Splash]

Is it sufficient to give those folds an extra brushing?

Sure!

 

[jeffchap]

You need to test and dose a minimum of 3x per day to SLAM. And the more the better. Your FC has been dropping too low between dosing and algae can regain a foothold. This is what is prolonging your SLAM.

 

[animous]

I initially posted because I thought FC wasn't dropping and new algae was appearing even at very high FC level (for my CYA level).

Thanks for helping me stick it out. I added bleach twice, sometimes three times a day and brushed every time. I alternated between bleach at the returns, and bleach around the perimeter. Three days ago the pool was opaque blue, and now it is almost entirely clear.

I read in another thread that algae can form a film to protect itself from FC, and thus the importance of brushing. I don't know if it's true, but it will motivate me to brush even when everything looks good. I initially thought running my "dumb" suction-side cleaner once or twice a week would be enough.

Bleach wins again!

 

[Texas Splash]

it will motivate me to brush even when everything looks good.

Yes, and I have been guilty of that very same thing. I tell pool owner to think of their teeth. They may look clean, but after not brushing for a while they get that film on them, so we brush. Pool surfaces are somewhat similar. Outside of SLAM moments, we don't have to brush the pool everyday, but every 3-4 days does help for algae prevention.

 

[koffey]

when I slam, I always brush and manual vacuum. always. In fact, I do this 3-4 times a week regardless.

 

[Mdragger88]

I initially posted because I thought FC wasn't dropping and new algae was appearing even at very high FC level (for my CYA level).

Thanks for helping me stick it out. I added bleach twice, sometimes three times a day and brushed every time. I alternated between bleach at the returns, and bleach around the perimeter. Three days ago the pool was opaque blue, and now it is almost entirely clear.

I read in another thread that algae can form a film to protect itself from FC, and thus the importance of brushing. I don't know if it's true, but it will motivate me to brush even when everything looks good. I initially thought running my "dumb" suction-side cleaner once or twice a week would be enough.

Bleach wins again!

Keep going until u pass ALL 3 end of slam criteria.
The more often u raise to slam level for your cya the more u will win & algae will lose.
You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

SLAM ON