Has anyone had calcium buildup anywhere in their systems pouring Cal Hypo into skimmer?

[DrWho]

Hi! I see no calcium buildup yet, but want to be on the lookout. Couldn't find enough 12% bleach this year (been using bleach 6 years), so went to 73% Cal Hypo for the first time. No matter how much I stir that stuff in a bucket, it won't fully dissolve for like 24 hours (even with repeated additions of water) and I don't want it to bleach my vinyl liner by just "sprinkling" it into the pool and brushing it because I've tried and I see some of that stuff undissolved sitting at the bottom for a day or so afterwards.

I know I'm going to get a lot of hate for this but I also have my trichlor in-line chlorinator cranked on full blast to get my CYA back up to 50 (I drain the pool down to 2/3 volume and then some organism is consuming *all* of my CYA over the 6 months of winter) and haven't had even a slight bit of dangerous pressure buildup in either the puck dispenser or the sand filter when simultaneously using Cal Hypo, Trichlor, and even adding the 2 jugs of liquid chlorine I did manage to get my hands on, into the return jets. Heck, I've even added water *to* the dose of cal-hypo powder in a bucket and don't see any dangerous "boiling and sputtering" exothermic reactions. I've even been adding a bunch of extra pucks into the skimmer basket right *after* dumping in the cal hypo to hurry up and get my CYA up before the sun burns off every last drop of chlorine I've managed to put in there....and I still see no evidence whatsoever of any pressure changes anywhere in my system and I keep a close eye on the gauge throughout the day. I think all the drastic warnings on not mixing different forms of chlorine refer to not mixing the pure form. If Cal Hypo is heavily diluted in water or sitting in your sand filter with bucketloads of water continually washing past it, and just a trace of trichlor leaching off the pucks and a trace amount of liquid bleach coming in from the pool...I just don't see it "nuke-ing" my equipment as others have claimed it would. Of course I leave my pump running 24 hours a day.

My calcium level is about 110 ppm at the moment. Our tap water around here has about 170 ppm if I recall. TA is 90 , CYA is at 10, pH 7.6, FC goes to 4 ppm after adding 1.5 pounds of Cal Hypo, drifts down to 1 ppm in a couple days. I will monitor that Calcium level as the season progresses and hopefully the panic hoarders will stop buying up all the 12% bleach by then. Maybe I need to scout a janitorial supply and find me some carboys. Although I haven't ever used carboys and not sure how you get just 1 gallon at a time to the pool (every other day) without bleaching my wife's basement carpet. Talk about a nuclear event.

 

[mariane]

Welcome to the forum.
Actually you won't get hate from using pucks. TFP just wants people (like you) to be aware of what you are putting in your pool. Many people don't know that CYA, sometimes copper, sometimes clarifier, is added to the pool along with the chlorine every time a puck is used. That's what causes the buildup of CYA, metals, gunk in filter, and then people can't figure out why their pool is turning green.

We don't HATE, we eduCATE.

 

[borjis]

Pucks in the skimmer can be especially dangerous for vinyl lined pools. When the pump isn't running you'll have super high levels in the skimmer and surrounding vinyl. One person ended up with the liner all cracked & broken up at the skimmer mouth and had to replace it.

 

[mariane]

Also, pouring high concentrations of chlorine in the skimmer can cause corrosion of metal. Cal-hypo might be the same thing.
TFP also lets people know:
"It's your pool and you can take care of it any way you want. We are here for you when you have questions and need help."
"TFP advice and pool store advice don't work together. Choose one or the other."

 

[DrWho]

Thanks Mariane, I appreciate your kindness. It's funny that over the years of reading/lurking in the Troublefreepool forums that I went from first regarding CYA as an anathema to pool chemistry, when it actually is sort of a necessary evil if you don't want the sun to burn off all your chlorine in a few hours. (This happened to me the first time I ever opened a pool, and couldn't figure out what was happening until I tested my CYA at zero ppm. I was simply *astonished* because it was over 120 ppm the previous season). I remember reading a scientific journal article online about some bacteria? that could metabolize CYA. And after discovering the pure gold treasure of Troublefreepool that first year back in 2014, I bought my first Taylor K2006 test kit and became much more aware of CYA levels and started using bleach at that time. I find the pure CYA dry chem not too cheap and very cumbersome to dissolve using the sock in front of the return jet method, and since I already have on hand some fairly fresh economical (Member's Mark?) Tri-chlor pucks, I figure I kind of get a two birds with one stone effect by raising my CYA up using the pucks to start the season. This year will be an experiment for me using Cal Hypo so much. I thought I remember a while back reading a post on troublefreepool about adding Cal Hypo directly to the skimmer, and someone made a brief comment on how they had been doing it and the result was a surprise buildup of calcium somewhere that they weren't expecting, but didn't say where or how they found it.

P.S. I have purchased 3 different brands of CYA test kits, including the LaMotte, Taylor, and Blue Devil, and I even bring a sample to Leslies, and a second store, (a local pool contractor brick and mortar retail store), and all 5 tests give completely different results. And the range of results I get is almost ludicrous, as in anywhere from 5 to 40. So in that case what is a poor pool chemist to do but take the "average" of all 5? I have repeated the tests I own and the repeatability is good for each separate test, however, the range of results amongst the 3 is still outside of my comfort zone as a former research grad student turned wife's pool boy. Edit: I recently found out that our local Leslies started this year using the LaMotte Waterlink Spin Touch lab with the little centrifugal spinning discs that looks very high tech, but some of the numbers still don't agree with my tried and true Taylor K-2006 kit readings.

 

[DrWho]

Pucks in the skimmer can be especially dangerous for vinyl lined pools. When the pump isn't running you'll have super high levels in the skimmer and surrounding vinyl. One person ended up with the liner all cracked & broken up at the skimmer mouth and had to replace it.

Very true, if my electricity went out unexpectedly, I'd be in trouble with all that acid just sitting there...but I keep my pump running 24/7 all season long, much to the chagrin of the electric company and my electric bill. My pump is located way way up hill from the pool and loses prime instantly if I shut it off (I have to close all 3 pump input ball valves immediately when cleaning out the pump basket). If this wasn't the case, I would probably only run my pump on a timer, 12 hours a day, probably at night while my chlorine is working as I tend to add chlorine in the evening. It takes manual intervention to re-establish prime once lost. Something I don't want to do every day so I just leave it running all the time.

 

[duraleigh]

So in that case what is a poor pool chemist to do but take the "average" of all 5?

Absolutely not!

1. Stay out of EVERY pool store. To count or rely on ANY test result from them can be VERY dangerous.

2. Use your Taylor kit and learn to interpret it. While the others may be fine, you are confusing yourself by all those tests. Virtually everyone on this forum uses Taylor Chemistry (The TF-100 uses Taylor, too). It is reliable, dependable and we can help you interpret the results. Don't get hung up trying to be totaly precise. The variation is plus or minus 10 PPM.

 

[mariane]

I find the pure CYA dry chem not too cheap and very cumbersome to dissolve using the sock in front of the return jet method, and since I already have on hand some fairly fresh economical (Member's Mark?) Tri-chlor pucks, I figure I kind of get a two birds with one stone effect by raising my CYA up using the pucks to start the season.

This makes sense but it can take up to a week for the CYA to build up enough to be useful, thus eating up the chlorine by the sun. As long as you know what is happening, you can watch it. But realize it's not without potential problems.
I dissolve CYA in a sock in the skimmer while running. Squeeze numerous times and it's dissolved in one day.

. . . . . adding Cal Hypo directly to the skimmer, and someone made a brief comment on how they had been doing it and the result was a surprise buildup of calcium somewhere that they weren't expecting, but didn't say where or how they found it.

Excessive calcium causes scaling, in heaters, pipes, metal stairs, that type of thing. It could build up very quickly on the innards of equipment with high concentrations being added in one place. Thus, don't add in the skimmer.

. . . . and all 5 tests give completely different results. And the range of results I get is almost ludicrous, as in anywhere from 5 to 40. . . . . I have repeated the tests I own and the repeatability is good for each separate test, . . . . but some of the numbers still don't agree with my tried and true Taylor K-2006 kit readings.

Store results are not accurate because of a number of reasons: calibration of the testing equipment, testers who do not take the time and detail in using the drops or strips, cross contamination of previous pool owner's water in testing. And I'm sure there are others.
You will be the most invested in getting the numbers right, "inter" tester accuracy (me, myself, and I sort of thing) and you are the one that has to swim in your pool. As you wrote - your test's repeatability is good.
The numbers don't agree. Well, they won't and you have already seen why. Your's are accurate, theirs are not.
You said it yourself "my tried and true Taylor K-2006 kit readings."

2. Use your Taylor kit and learn to interpret it. While the others may be fine, you are confusing yourself by all those tests. Virtually everyone on this forum uses Taylor Chemistry (The TF-100 uses Taylor, too). It is reliable, dependable and we can help you interpret the results. Don't get hung up trying to be totally precise. The variation is plus or minus 10 PPM.

As duraleigh posted, you're confusing yourself with the store results.
Trust your own numbers.