Precipitated Calcium?

[Methuselah]

On our initial fill about 6 months ago we didn't purge first or wipe down the waterline. With ~30 ppm cya we targeted 6-6.5 chl if getting in, 5 if not, twice a day. Demand ate about 1-1.5 if we didn't get in. I figured the ozone generator was mostly responsible.

Within 2-3 months we got foam when running pumps, so pushed ch up to 130-140 range. ALK was 40-50. Foam became minimal only showing with the pumps running and quickly dissipated.

Fast forward 6 months

We just dumped and refilled first time. There was a white film on the skimmer assembly I presume was precipitated calcium. That film is probably on my heater element too? We had also dumped borites in so could the film be related to that too?

Pool store says ch is 89, ALK adjusted to 52. I wonder if i should add any more ca (no foam for now) or keep checking to see if CH rises due to leaching off pipes or heater?

I'm also now wondering if the borites are really necessary(?). I added only after acid/aeration to set ph/alk. For now ph seems to be behaving.

Btw, we purged with ah some! and demand is closer to .25-.5 on low side, maybe ~.75-1 on high side. Shout out to ah some!

I suppose I need to add that I had a rash down there, wife didn't. After self-treatment with tinactin I wash after getting out. Maybe it was bio film or maybe I had it prior to initial fill - no way to tell. That said, we did see evidence of a little bio film release and more when magic sponge wiping sides after pumping out and refilling. We plan to try and keep up with wiping down the waterline. Wish i could say the same for the filter but tear in rotator cuff and now maybe flu, better half not keen on stepping up to weekly filter clean/swap (i know, i know - people soup...).

Methuselah

 

[Ahhsomeguy]

Thanks for the info Methuselah: Hot tub rashes, especially down there, can be an issue. Glad your wife escaped It. Your tub is a good size so you may want to purge every 6 months or so. Master Spas Corporate are good people. We have dealt with their customer service people for many years. Kirk is a great guy.

 

[Mdragger88]

What has your ph been?
How did you add borates? Borax or boric acid?

 

[Methuselah]

Thanks for the info Methuselah: Hot tub rashes, especially down there, can be an issue. Glad your wife escaped It. Your tub is a good size so you may want to purge every 6 months or so. Master Spas Corporate are good people. We have dealt with their customer service people for many years. Kirk is a great guy.

Well, to be clear, rash was about the time of initial fill. The hot tub hadn't been purged.

The recent Ahh-some! purge lowered chl demand

I don't know that I still need to wash after a soak, but it was one heck of a rash so maybe worth erring on the side of caution...

Any idea if Kirk at Master Spas would know about the ch/borites?

 

[Methuselah]

What has your ph been?
How did you add borates? Borax or boric acid?

Did the muriatic acid aeration dance so ph started at 7.5, maybe drifting up toward 7.6 lately. It was 100% boric acid on the label (ant poison).

 

[Mdragger88]

Being on top of ph, The low ch & The addition of boric acid should only help lessen the possibility of scale formation not increase it - however, even though the label lists ant/roach killer as 100% boric acid that doesn’t necessarily mean that’s the case

Borates in pool - Further Reading

www.troublefreepool.com

I have used it in the past before I knew better & never experienced what you saw however products change regularly.
To avoid potential issues from undesirable additives stick with technical grade 100% granular boric acid from somewhere like dudadiesel.com. Bulk apothecary also sells 100% boric acid but it’s generally powdered which is harder to dissolve although that’s not a huge deal with the small amounts needed in a spa.
Since the residue wiped off I doubt it was scale.

 

[Methuselah]

@Mdragger88 I do recall reading that and deciding to "roll the dice". I think I had looked up the MSDS and it said 99% boric acid. I suppose I could call and ask them?

Now that I think about it, I probably could have taken a water sample to the pool store and most of the difference between readings at time I added would be precipitation? Too late, but next time?

Still same unanswered question though, could borites precipitate, and does it help that much?

Other "equations" will come into play will be choosing a targt CH if/when I get foam again (since I purged and didn't do enzyme or metal out stuff on this 1st refilling). Reckon if I do get foaming, since calcium helped, I'd add incrementally. By the same token, hopefully getting the water tested again after letting it run a month or two would suggest it was definitely calcium if the CH number rises without having added any(?).

 

[proavia]

How are you testing the water?
Post a full set of current test results from one of the recommended test kits.
Test Kits Compared

FC
CC
pH
TA
CH
CYA

Copper/zinc mineral stick, MPS and enzymes aren't really helping you.

 

[Methuselah]

How are you testing the water?
Post a full set of current test results from one of the recommended test kits.
Test Kits Compared

FC
CC
pH
TA
CH
CYA

Copper/zinc mineral stick, MPS and enzymes aren't really helping you.

fc 6
cc 0
ph 7.6
ta 52
ch 89
cya 32

Drop test for chl, pool store on ch and ta (but very close to expectations based on how much acid was used last time).

Nut sure how that helps though, it's LAST fill with 6 months use that was in question.

 

[proavia]

Without accurate test results from one of the recommended test kits, there is really no telling exactly what might be happening.

Pool store tests have proven time and again to not be accurate or repeatable. You can take the same sample of water to three different pool stores and get three different results.
We don't offer advise based on pool store testing.

Seriously consider getting one of the recommended test kits and take charge of your spa.
While it's your spa and most certainly your choice on how to manage it, we can help if you follow the TFP methods - and it all starts with accurate testing using one of the recommended test kits.

 

[Methuselah]

Without accurate test results from one of the recommended test kits, there is really no telling exactly what might be happening.

Pool store tests have proven time and again to not be accurate or repeatable. You can take the same sample of water to three different pool stores and get three different results.
We don't offer advise based on pool store testing.

Seriously consider getting one of the recommended test kits and take charge of your spa.
While it's your spa and most certainly your choice on how to manage it, we can help if you follow the TFP methods - and it all starts with accurate testing using one of the recommended test kits.

Gotta cry foul on that one guy, test kit matched pool store for CYA +/- 1 ppm at low 30's several times, and I calculated CH based upon weighing Calcium before adding and retested at pool store, extrapolated difference and added again, their result thereafter matched pretty good. CHL is measured with a Taylor DPD drop test and matches the OTO kit when it's in range of it. I did use chemicals to check the ALK and pool store also matched it most of the time (so when they were off once I used my calculation). Boric Acid was measured by weight only, 1# in 515 gallons put it in the 40's (iirc ?).

The precipitation question (calcium or boric acid), is not based upon the numbers you requested, but the previous fill before I dumped and purged at the 6 month mark.

Reason for tying my current question to the new fill is I might get foam again, probably from body oils, soap residue, etc. and if general consensus is 140'ish CH is going to precipitate on the pipes and heater like the filter housing where I found it, maybe I should only add enough calcium in small steps if it begins foaming again.

On the other hand, if general consensus is it may have been borites, then 1) do I really need borites if PH doesn't drift much, or 2) maybe I should consider a flocculent. Since it started foaming at the one or two month mark on initial fill, I don't want to consider dumping and refilling that often so I am kinda hoping smarter people than I am can help ID what's going on. Please consider the test numbers in my first post as ballpark or close enough, the worst that could happen is their a little off but I'm pretty sure they are not off by a magnitude.

Thanks,
Methuselah

 

[Methuselah]

@JoyfulNoise would love your opinion?

 

[mgtfp]

Pool store says ch is 89, ALK adjusted to 52.

Ignore adjusted ALK. If CYA of 30 is correct, then your TA is above 60. Adjusted Alkalinity is only required for manual CSI calculations, for example with the Taylor wheel. If you put adjusted Alkalinity into any CSI calculation app, you'll subtract CYA-Alkalinity twice. And for buffering purposes, unadjusted, real TA counts. As you get it straight from the Taylor drop test.

And recommendations here on TA levels are always based on Total Alkalinity, no adjustments, as the word "Total" implies.

 

[mgtfp]

And Borates complicate things further. Considering Borate Alkalinity, your TA is probably closer to 70. So, if your Taylor results and the Pool Store results line up, then something is wrong. Let's say you tested 50, then the pool store should tell you something like 40 as adjusted Alkalinity (they don't know about your Borates, and don't even bother correcting for Borate Alkalinity).

In short: Don't use Pool Store results for discussions on TFP, it just complicates things. No one will want to answer your actual questions based on test results they don't trust. All you get is information about pool store testing.

Especially when using Borates, it is important to do your own testing and use PoolMath to calculate required amounts of acids.

When you say Taylor drop test for chlorine, is that FAS/DPD with powder and drops, or just DPD with drops only?

 

[Methuselah]

And Borates complicate things further. Considering Borate Alkalinity, your TA is probably closer to 70. So, if your Taylor results and the Pool Store results line up, then something is wrong. Let's say you tested 50, then the pool store should tell you something like 40 as adjusted Alkalinity (they don't know about your Borates, and don't even bother correcting for Borate Alkalinity).

In short: Don't use Pool Store results for discussions on TFP, it just complicates things. No one will want to answer your actual questions based on test results they don't trust. All you get is information about pool store testing.

Especially when using Borates, it is important to do your own testing and use PoolMath to calculate required amounts of acids.

When you say Taylor drop test for chlorine, is that FAS/DPD with powder and drops, or just DPD with drops only?

I misspoke or you misread... I didn't say Taylor, or "adjusted ALK", I said (meant?) I adjusted it (by dumping muriatic acid in). Kit was an old Walmart thing, result just "ALK". pool store matched ALK close, numbers as they changed while I was adjusting tracked each other and the expected amount of change from the old calculator on this site.

Chl kit is powder and drops, results match oto kit, sample is usually weaker by the time it's dropped by the pool store.

So, if ALK was low 40's, was it CA, borites, both...

BTW, as stated by Mdragger88, the boric acid I used could have been "inaccurately reported" on the MSDS sheet (I'll have to contact the manufacturer), it was labeled as ant poison. Another monkey in the wrench...

I read if it's blue powder it's a mix, at least it wasn't the blue stuff so maybe I got lucky.

My expertise on this subject is right up ther with the amobia, but I hope I provided enough info for an educated guess by those who are more educated than I (everybody here)?

 

[mgtfp]

I misspoke or you misread... I didn't say Taylor, or "adjusted ALK", I said (meant?) I adjusted it (by dumping muriatic acid in). Kit was an old Walmart thing, result just "ALK". pool store matched ALK close, numbers as they changed while I was adjusting tracked each other and the expected amount of change from the old calculator on this site.

Chl kit is powder and drops, results match oto kit, sample is usually weaker by the time it's dropped by the pool store.

So, if ALK was low 40's, was it CA, borites, both...

BTW, as stated by Mdragger88, the boric acid I used could have been "inaccurately reported" on the MSDS sheet (I'll have to contact the manufacturer), it was labeled as ant poison. Another monkey in the wrench...

I read if it's blue powder it's a mix, at least it wasn't the blue stuff so maybe I got lucky.

My expertise on this subject is right up ther with the amobia, but I hope I provided enough info for an educated guess by those who are more educated than I (everybody here)?

Bit confused here. I was going by "Pool store says ch is 89, ALK adjusted to 52."

Usually pool stores won't tell you what the Alkalinity will be after adding acid. When they say "adjusted", they mean that they "adjusted" the actual TA measurement by subtracting CYA-Alkalinity and are therefore actually reporting Carbonate Alkalinity and not Total Alkalinity. In case they don't test for Borates, they will actually report Carbonate Alkalinity plus Borate Alkalinity, should Borates be in the water that they don't know about (but they will wrongly interpret this as Carbonate Alkalinity only).

Regarding the boric acid, it will still have added pretty much the right amount of boric acid. There might be a minuscule amount of something you might not want in your pool. But if they report 100%, then it should be 100%, otherwise they'd actually be lying. If there are other deliberate additives, they should say for example 99% boric acid plus 1% other ingredients that by law don't have to be listed by name as long as they are not considered hazardous. An MSDS only has to list hazardous substances, but I don't think they are allowed to lie about the percentages, di 100% should be pretty clear

But there might be other contaminants they don't really care about in an ant killer product.

 

[Methuselah]

Fast forward, looks like I have an answer

We have a new pool store reading:

1) CH of my water from the tap was 89
2) I'm going to assume it was a good number because, well, feel free to reread previous...
3) I'm going to assume my tap water has not changed (I'm scientifically mined, but you gotta draw a line in the sand SOMEWHERE)
4) I'm going to assume if after these two months+ that if CH is higher, it's because it had precipitated before, and has now dissolved back into the new fill water.
5) I'm going to remind you good folks I wiped off some white powder coating my filter housing and float-sleeve. Lets call it an arbitrary 10% removal and guestimate another 1% splashout.

The new reading for CH is (drum roll please) ; 101

6) I'm going to assume it's a good number (see #2)

The verdict and lessons learned

The precipitation was calcium. At 89 it was not happening, and at levels needed to stifle foaming, 130-140, it ended up deposited in my plumbing (and heater) to the tune of about everything over 127, per math on calculator.

Apparently the level of calcium needed to stifle foaming is a fine line once crossed, will precipitate inside the plumbing.

What I didn't learn was if there were "adjustments" to be had that could render a "buffer zone" between enough and too much.

SO, ANY THOUGHTS WELCOMED, the players were, CL, CA, PH, CYA, Boric acid, MPS, MA, and sadly, some metals removal (j)unk and enzyme treatment (j)unk. Lost cause?

Players this fill will be more limited, so maybe this horse opera runs another season...

 

[Mdragger88]

I would stick with handling the fc, keeping ph in the 7’s with Muriatic acid, work on lowering actual ta to 50 to assist, once that’s done you can add pure boric acid (no bug stuff) & leave ch as it comes from the tap. If you’re purging with Ahhsome sometimes there can be a little residual remaining after refill that causes foaming but it will subside. I don’t “bump” my pump when the tub is empty to expell what’s in the lines cuz I’m skeered lol so I just try to put the hose on each jet for a minute after draining then put it in the inlet (where the filter is) so it flows out of each jet then drain that water before refilling.
No mps (chlorine is a pretty good oxidizer) or enzymes & STAY OUTTA THE POOL STORE! Test your own ACTUAL ta,ch, & cya.
I see you have a partial kit, all you need is a beakers & reagents. But For the price of getting them all separately you could just get a kit with everything included & end up with spare fc reagents which are what get used up fastest anyway.

TF-100 Test Kit

tftestkits.net

Unless you have an obvious metals issue arise no need for metals treatments.
Keep it simple & see where that gets you.

 

[proavia]

We don't provide advise based on pool store testing. It has proven time and again to be inaccurate and not repeatable.

You state you are scienticic minded, but are making a lot of assumptions - based on pool store testing. If you are serious about keeping your tub sanitary and basically trouble free, get a good test kit (Test Kits Compared), ditch the "mineral pack" and MPS.

Being only 515 gallons, its easy to drain/refill - and should be done every 6 months or so.
Have you ever purged your tub with Ahhsome to rid it of biofilms?

 

[Methuselah]

I would stick with handling the fc, keeping ph in the 7’s with Muriatic acid, work on lowering actual ta to 50 to assist, once that’s done you can add pure boric acid (no bug stuff) & leave ch as it comes from the tap. If you’re purging with Ahhsome sometimes there can be a little residual remaining after refill that causes foaming but it will subside. I don’t “bump” my pump when the tub is empty to expell what’s in the lines cuz I’m skeered lol so I just try to put the hose on each jet for a minute after draining then put it in the inlet (where the filter is) so it flows out of each jet then drain that water before refilling.

Yeah, I too am not one to tempt fate ... I don't bump the pumps either.

This is only my 2nd fill, most (j)unk was a onetime deal, i.e. concern for possible metals due to manufacturing process. Also, no purge initially.

No mps (chlorine is a pretty good oxidizer) or enzymes & STAY OUTTA THE POOL STORE! Test your own ACTUAL ta,ch, & cya.

Just put 4 oz MPS, was seeing a little persistence with low levels of CC. Can't stay out of pool store, don't have a kit for CH. They do good on testing that, fairly good on CYA.

I see you have a partial kit, all you need is a beakers & reagents. But For the price of getting them all separately you could just get a kit with everything included & end up with spare fc reagents which are what get used up fastest anyway.

Ben Powell sold me a DPD kit, Wallyworld also (ALK, CYA, CH, CL). The CH reagents are too old.

TF-100 Test Kit

tftestkits.net

Unless you have an obvious metals issue arise no need for metals treatments.
Keep it simple & see where that gets you.

I definitely believe in the kiss principle .

Still though, MSDS says my bug poison is 99% so may just keep using it.

As I said, I see CA as a decent solution to foaming, just trying to figure out if tweaks can widen the range between it being effective and the point where it will no longer stay in the water.