SLAM Management

[SpaWife]

I'm new to the TFP Protocol, and am loving it! I'm almost 3 months in to it, and am not even pondering draining & refilling like I used to have to do. (Pre-TFP protocol I had to drain & refill sometimes monthly, and definitely by the end of 2-2.5 months ... now I realize due to high CYA).

I have been trying to SLAM once a week, as recommended. Is this the same as shocking? Or rather, does it serve the same purpose as shocking?

I SLAMed this morning - added enough chlorine that Pool Math's Effects of Adding said would get me to 17 FC (1.33 cups of 7.5% bleach, since I started at 0 oops). I was confident in how my numbers had been steady really for a couple months (it was perfectly balanced 3 days ago: 7.2 pH, 50 alk), so I didn't bother testing it before adding the chlorine. Well, I did do a test-strip which showed 0 chlorine.
I let that circulate, did some errands, and have now come back to evaluate.

Here are my afternoon numbers:
9.2 pH (WOW - that's high! It had been 7.2 just 3 days ago when I last tested. Is the higher pH because of my addition of 1.33 cups of bleach today? Will that go away?)
50 alk
175 hardness
19.5 FC (oops! That's higher than the 17 I was aiming for..)
1.5 CC (I've been carrying a 1.5 CC for a month, and for the month before that I'd been carrying a .5 CC)
30 CYA (It had been at 40 CYA, although I just re-tested and realized it's at 30. Maybe due to having added water a week ago?)

My main question is about the pH... Will it settle once that chlorine cooks off? I've tried to learn not to over-react to numbers since that results in the yo-yo game. But obviously that pH is way too high! If I adjust it with pH decreaser, the alkalinity will also go lower, right?

So what is my next step? I was just trying to get the chlorine back up (with the dual purpose of shocking/SLAMing it). And now I'm stumped. Will the pH come back into line? Will that excess chlorine cook off? Should we not get into the hot tub for the rest of the day... or even tomorrow also? Do I just wait? Should I do something to help it get back into good numbers (ph & chlorine)? I currently have the cover open and am running the jets.

 

[Texas Splash]

Remember, we only increase the FC to SLAM level when we have algae and actually need to do the SLAM Process. If you don't have algae, simply maintain the FC as noted on the FC/CYA Levels.

 

[Texas Splash]

Also, the pH test is skewed when your FC is over 10. Don't try to test or adjust the pH until the FC drops to 10 or below.

 

[SpaWife]

Remember, we only increase the FC to SLAM level when we have algae and actually need to do the SLAM Process. If you don't have algae, simply maintain the FC as noted on the FC/CYA Levels.

No kidding?! I wonder how I got it in my mind that it should be done weekly.

Is a weekly shock (MPS) needed?

 

[Newdude]

I wonder how I got it in my mind that it should be done weekly.

Because it's in the Spa sticky thread.

Sanitation
On a fresh fill use Dichlor until you get to 20-30 ppm CYA. (10 ppm FC = 9 ppm CYA)
Then switch to plain bleach or liquid chlorine.
Never let FC drop to Zero for any length of time. Keep it between 3-6 ppm normally, min of 1 ppm, and shock to 12 ppm once a week.
Use MPS if needed before hot tub party's and/or once a week to help oxidation

It needs an update as we've moved away from unnecessary shocks/slams.

Also, I'd like to comment that with regular use, 3 months on tub water is fair. You're not enjoying a relaxing soak, you're making people soup.

Before my hot tub I thought we and our suits were clean when freshly washed. We both were full of residual soaps/conditioners. Sitting in 100+ degree water makes us sweat and the bubbles exfoliate dead skin and wash off body oils. Then add a slew of bacteria and a few spills of a margarita and yeah. 3 months is fair. At some point the chemistry will get away from you no matter what, and you're advised to dump at the first signs of not being able to easily correct it. If the tub has very light use, then up to 6 months may be possible.

 

[JoeSelf]

MPS will give false high CC numbers. MPS is an oxidizer. Chlorine is both sanitizer & oxidizer. Others here don't use MPS. I don't use MPS since my tub has ozone.

 

[Mdragger88]

Are you using strips for ph? How did you get a reading in the 9’s?
On the FC front…
To clear things up,
SLAM means Shock Level And Maintain
If you’re not Maintaining then you just reached Shock level (for your cya I suppose) FC/CYA Levels
This is generally unnecessary on some arbitrary schedule when proper sanitation is always followed.
** except that you said fc went below minimum **
- in that case you would raise to shock/slam level for your cya in an attempt to rid yourself of any nasties that have proliferated in that time.
You should do this until your water is
1)crystal clear
&
2) your cc’s are .5 or less.
You cannot really do an OCLT in a spa as it eats fc all the time at a higher pace than a pool so that’s not a
SLAM Process criteria you need to meet.
This may only take once or multiple rounds of raising to shock/slam level.

*However* - if fc demand begins to seem excessive it may be time to purge & start over. The same goes for persistently elevated cc’s.

 

[SpaWife]

Because it's in the Spa sticky thread.



It needs an update as we've moved away from unnecessary shocks/slams.

Also, I'd like to comment that with regular use, 3 months on tub water is fair. You're not enjoying a relaxing soak, you're making people soup.

Before my hot tub I thought we and our suits were clean when freshly washed. We both were full of residual soaps/conditioners. Sitting in 100+ degree water makes us sweat and the bubbles exfoliate dead skin and wash off body oils. Then add a slew of bacteria and a few spills of a margarita and yeah. 3 months is fair. At some point the chemistry will get away from you no matter what, and you're advised to dump at the first signs of not being able to easily correct it. If the tub has very light use, then up to 6 months may be possible.

Okay. Thanks! I knew I hadn't just made it up. But I'll take note that I shouldn't do that.

I do agree about people soup. I don't mind a 3 month purge & drain. (And I'll keep an eye out for levels becoming squirrelly.) But before TFP, I was having to do it monthly (when using the Frog) and then every 2 months (without the frog, but still CYA getting jacked up sky-high from the pool-store & other online advice of needing to do at least weekly MPS and daily dichlor). So I'm very content that I'm at 3 months and my water isn't even starting to smell weird and make me sneeze uncontrollably.

 

[SpaWife]

Are you using strips for ph? How did you get a reading in the 9’s?
On the FC front…
To clear things up,
SLAM means Shock Level And Maintain
If you’re not Maintaining then you just reached Shock level (for your cya I suppose) FC/CYA Levels
This is generally unnecessary on some arbitrary schedule when proper sanitation is always followed.
** except that you said fc went below minimum **
- in that case you would raise to shock/slam level for your cya in an attempt to rid yourself of any nasties that have proliferated in that time.
You should do this until your water is
1)crystal clear
&
2) your cc’s are .5 or less.
You cannot really do an OCLT in a spa as it eats fc all the time at a higher pace than a pool so that’s not a
SLAM Process criteria you need to meet.
This may only take once or multiple rounds of raising to shock/slam level.

*However* - if fc demand begins to seem excessive it may be time to purge & start over. The same goes for persistently elevated cc’s.

No. I can't read pH levels on test strips - my eyes just can't make sense of it.
I had been using the circular comparator that came with my K-2006 testing kit, and then using the decrease/increase-demand test to do a guesstimate of just how high the pH was.
Recently I've been trying to become friends with the square-ish comparator that my TFTestKit came with.
BUT just in the last week I've been using the yellow pH meter that I bought from TFTestKits (which I did calibrate, as well as I've been testing it against my circular comparator that I'm well acquainted with).

SO the pHs I've shared with you in this thread are using the yellow pH meter.

Yes I did let the FC get to 0, and that did motivate me today to reach the shock/SLAM number for chlorine. Although I'd been doing well keeping levels above the min over the last month or so, the last week I let myself slip... and today I was trying to get things back in order. My water has been crystal clear since I drained & refilled and began TFP protocol 3 months ago.

Good to know that SLAM isn't necessary if above-min is always maintained. I had been wondering that.

I did not know that OCLT isn't a spa thing. Thanks for sharing that.

Thanks for the info on when to purge & drain. How high is a persistently elevated CC?

 

[Newdude]

How high is a persistently elevated CC?

That's tricky in a hot tub with the insane bather waste. 2 people in 500 gallons is the same as 136 in my 34000 gallon pool. And the pool people are cooling down, not heating up. Lol. People soup I tell ya !!!!

But all that residual bather waste is consumed by chlorine, making CCs. So it's almost expected to have 2 to 3 CCs for a day or so after a soak. Then the tub spends most of its life covered where the sun can't burn off the cc's and it's really hard to quantify the difference between normal and a problem in a spa. Although, if you haven't used the tub all week but suddenly have CCs, then it could be an issue.

The best you can do is stay free and clear above minimum at all times. Dose higher than target before a soak and SLAM after. Check the next day to ensure you're still in target range.

 

[Mdragger88]

Recheck the ph with the taylor drop test after the tub has been still a bit & fc is below 10ppm to be sure your getting an accurate reading & its not skewed by high fc.
While the acid demand thingy seems helpful, you should instead use
PoolMath & use the highest value on the comparator block as your “current” then set your “target” at mid 7’s so you don’t risk over dosing acid as there’s not alot of wiggle room with such a small body of water.
Retest in 10 or 15 minutes and repeat until you get a readable ph.

As far as persistent cc’s go in my experience 0.5- 1.0 ppm consistently even when there hasn’t been a bather load is an indicator it’s getting around to purge & dump time even if the water looks fine especially if they stick around even after going to slam level a time or two.
As Newdude mentioned- testing right after a long soak or immediately upon opening the cover is going to show some cc’s usually. So I open the cover and come back in a little bit to get a baseline. Its a good idea to open the spa up & let the cc’s out “let it breathe” when you get a chance anyway. I spend alot of time on the patio so it’s no inconvenience.

 

[SpaWife]

Thanks for all of the info. The nuanced advice is helpful.

The water is currently at 8.3 pH and 12 FC, 2 CC. This is 9.5 hours after I put the bleach in. So it's trending in a good direction. I'll test again tomorrow morning, before I decide if pH intervention is necessary.

I did leave the cover off for most of the day, to try to let it breathe. I'm glad to read that that was probably helpful, even if it did catch a bunch of flies.

 

[Gebo]

SpaWife, I’m trying to understand what you did “wrong.” Can you help me understand? Was it when you accidentally got down to 0 chlorine and that just threw things out of whack?

 

[SpaWife]

SpaWife, I’m trying to understand what you did “wrong.” Can you help me understand? Was it when you accidentally got down to 0 chlorine and that just threw things out of whack?

I think the #1 problem was letting it get to 0 chlorine. Then my 2nd problem was overcorrecting by adding too much chlorine (with the idea of SLAMing, which was also wrong since apparently we don't need to SLAM unless there's algae; but I also overshot the SLAM #). Those were what I did wrong. I believe the overcorrection led to high pH, which is what brought me to start this thread.

 

[PoolStored]

I believe the overcorrection led to high pH

It did and it didn't.

The pH test will show a false high (the pH test is invalid) when your FC >= 10. So only test pH when FC < 10.

The fact that your FC was high led to a false pH reading. High FC doesn't cause high pH.

 

[Mdragger88]

& raising fc to slam level in your situation (zero fc & elevated cc) was the correct action.
until cc is reduced (0.5 or less - or at least down to 1 ppm if that’s what you were getting before) & the water is crystal clear you would continue with slam level.