SLAM(ish) and adjusting other levels

[D2424]

I have been performing the SLAM process for the first time this year. I began the process 3.5 days ago starting with getting the CYA up and PH down. My CYA is at 40 so my FC should be at 16. I'll admit I have not done a great job at keeping it there consistently but the water is improving. I can see the bottom of the deep end but it's still cloudy. Here are my current levels:

FC 13
CC 0
PH (off the chart low, which I've read here will happen with those FC levels)
TA 40
CYA 40

Based on the above, I have a few questions. I will be sure to kick the FC back up to 16 and do an OCLT tonight/tomorrow.

1. I have been running my Dolphin frequently to clean out any dirt and dead algae. Is it worth cleaning my filter cartridges as well at this point or will it not make a difference this early? The filter pressure gauge is fine (it has never gone above 2 psi at any point unless I close off one of the return lines) and the flow seems good.
2. Should I be running my filter 24/7 at a consistent speed? It still is using timer settings from last year. It is always running but shifts into lower speeds at times (around 1400 rpm at its lowest).
3. I need to get my TA up, but should I do it now or wait until the water is clear and SLAM is over?
4. Is it safe for swimming at these levels? Too cold for me, but the kids are getting restless.

 

[bobloblaw42]

1. What is your starting clean filter pressure at max rpm? When your filter psi goes up 20 to 25% above clean pressure at max rpm, then it is time to clean.
2. Pump running during SLAM is important part. No need to be at a constant low or constant high.
3. Wait until SLAM is over, don't want to introduce any additional variables getting to crystal clear.
4. Comfort aside, safe to swim up to and including SLAM FC levels for your CYA.

 

[Bperry]

I have been performing the SLAM process for the first time this year. I began the process 3.5 days ago starting with getting the CYA up and PH down. My CYA is at 40 so my FC should be at 16. I'll admit I have not done a great job at keeping it there consistently but the water is improving. I can see the bottom of the deep end but it's still cloudy. Here are my current levels:

FC 13
CC 0
PH (off the chart low, which I've read here will happen with those FC levels)
TA 40
CYA 40

Based on the above, I have a few questions. I will be sure to kick the FC back up to 16 and do an OCLT tonight/tomorrow.

1. I have been running my Dolphin frequently to clean out any dirt and dead algae. Is it worth cleaning my filter cartridges as well at this point or will it not make a difference this early? The filter pressure gauge is fine (it has never gone above 2 psi at any point unless I close off one of the return lines) and the flow seems good.
2. Should I be running my filter 24/7 at a consistent speed? It still is using timer settings from last year. It is always running but shifts into lower speeds at times (around 1400 rpm at its lowest).
3. I need to get my TA up, but should I do it now or wait until the water is clear and SLAM is over?
4. Is it safe for swimming at these levels? Too cold for me, but the kids are getting restless.

You should not be testing anything other than FC during a SLAM. All the other stuff can wait. Clean the filters and brush and vaccum as often as practical.

 

[D2424]

1. What is your starting clean filter pressure at max rpm? When your filter psi goes up 20 to 25% above clean pressure at max rpm, then it is time to clean.
2. Pump running during SLAM is important part. No need to be at a constant low or constant high.
3. Wait until SLAM is over, don't want to introduce any additional variables getting to crystal clear.
4. Comfort aside, safe to swim up to and including SLAM FC levels for your CY

1. What is your starting clean filter pressure at max rpm? When your filter psi goes up 20 to 25% above clean pressure at max rpm, then it is time to clean.
2. Pump running during SLAM is important part. No need to be at a constant low or constant high.
3. Wait until SLAM is over, don't want to introduce any additional variables getting to crystal clear.
4. Comfort aside, safe to swim up to and including SLAM FC levels for your CYA.

My pressure is usually around 2 psi. Right now it's showing about 2.25 psi. I always thought it needed cleaning when the gauge hit 8-10 PSI above the normal baseline level, which is why the gauge has that 2nd indicator hand. I'll give it another day or so and then give it a cleaning.

 

[bobloblaw42]

That 10psi is a rule of thumb that doesn't pass muster here at TFP. It's a one size fits all answer and we prefer to give guidance that is applicable to your pool, hence expressing it as a percentage of your actual baseline pressure at high pump speed.

 

[D2424]

That 10psi is a rule of thumb that doesn't pass muster here at TFP. It's a one size fits all answer and we prefer to give guidance that is applicable to your pool, hence expressing it as a percentage of your actual baseline pressure at high pump speed.

Thank you. That's good to know. Of course, seeing that 25% increase is not as obvious when your baseline is 2psi
I'll probably give the filter a cleaning tomorrow. It's definitely much clearer now, but not crystal clear. The CC is 0 and the FC held at about 17-17.5 overnight. I'll run my Dolphin a few more times today as well.

 

[Bperry]

Thank you. That's good to know. Of course, seeing that 25% increase is not as obvious when your baseline is 2psi
I'll probably give the filter a cleaning tomorrow. It's definitely much clearer now, but not crystal clear. The CC is 0 and the FC held at about 17-17.5 overnight. I'll run my Dolphin a few more times today as well.

Thats why you turn the speed up to full power and check the pressure. Back in the day, all pumps were single speed and so there was no one running at 2psi.

 

[D2424]

I think I am good on the SLAM. The water is clear, CC is 0, OCLT passed yesterday. FC is now coming down a bit on its own. It's at about 12.

As for pH, at what FC level will the pH test be reliable? Right now it is showing 7.0 at most, but I know the high FC levels during SLAM affect pH tests. Is a pH test at FC of 10-12 going to be accurate? I want to be sure before I increase the TA and then pH.

 

[Mdragger88]

Wait until fc falls to 10ppm or below before testing ph.
If you increase ta to 50 with baking soda your ph will likely recover on its own. It may also do so at a ta of 40.
There’s no reason to increase ph with another chemical.
Any ph in the 7’s is ok.
With kids splashing & pointing the jets up to aerate the water your ph will likely be mid 7’s soon without increasing ta.

 

[D2424]

Wait until fc falls to 10ppm or below before testing ph.
If you increase ta to 50 with baking soda your ph will likely recover on its own. It may also do so at a ta of 40.
There’s no reason to increase ph with another chemical.
Any ph in the 7’s is ok.
With kids splashing & pointing the jets up to aerate the water your ph will likely be mid 7’s soon without increasing ta.

Thank you. I'll go the TA route with the baking soda and monitor pH.