calcium/taylor test kit question

[anne]

I dumped and refilled a few days ago, and realized that I forgot until now to check the calcium level. Oops. When I refilled, my pH was 7.4, TA was 100 or so, without adding anything! Nice. So I just added a little chlorine, waited two days, then put in the N2 unit with a dose of MPS. I knew there was some reason to delay adding th N2, but couldn't  remember what it was. Delayed it anyway.

Today I remembered to check calcium. I use the taylor kit, and did the measurement twice. Everything is fine adding the 20 drops of #10, then 5 drops #11L, but then both times, something precipitated as I added #12 to watch it change from pink to blue. It was like it went from a pink solution, to a clear solution with tiny pink bits (it would look like a solution from a distance) to the bits turning blue. If I ignore the precipitation issue, and just look at the over all color of the stuff, my Ca is 400-450. But I dont remember precipitation before.

The only difference I can think of is that the N2 unit has been in there 24 hrs.

What gives? Is my tub going to fall apart?

[Pathfinder]

Ive noticed particle suspension in calcuim testing quite often when calcium is too high  or when a bottle as been sitting too long in improper conditions.   If you live close to your dealer get them to test it and see if it doing the same thing if not  then you should get new refills for your calcium reagents.  Thats just my take.

450ppm is really quite high

[Reese]

Try the alternate protocol for expected high calcium values, which uses half the reagents.  I've found that to be adequate for determining approximate levels (and it limits the risk that I'll get distracted and lose count before I get to 20 drops , and perhaps will limit the precipitation problem.

[Vinny]

What was the chlorine level?

Chlorine can play havok with the other readings.

[anne]

I'll do it again tomorrow, testing Chl at the same time, and I'll check pure tap water, too. I doubt I had more than 1-2 ppm chl at the time I tested today, as my last soak before that had been the morning before.

I tried shaking up the test kit bottles- no difference. I have only had the kit one year, so i hope that the reagents are not old.

I have had Ca levels higher than 450, with no ppt in the past.

hmmm.

[Reese]

...When I refilled, my pH was 7.4, TA was 100 or so, without adding anything!...  

Have you tested the pH and TA since the initial fill?  My tub shows levels like that out of the tap, but its true high pH/TA shows up a day or two later.  If so, the precipitation could just be an indication of unbalanced water.

[Chad]

 I have only had the kit one year, so i hope that the reagents are not old.  

I was told that the reagents are only good for one year.

[anne]

Have you tested the pH and TA since the initial fill?  My tub shows levels like that out of the tap, but its true high pH/TA shows up a day or two later.  If so, the precipitation could just be an indication of unbalanced water.

When I did the initial test, it was actually 1.5 days after refilling. I did not check anything immediately.

Right now:

tap water: pH 8+, TA 80, Ca 500, no ppt
tub water: pH 7.4, TA 60, Ca 500 WITH ppt, Chl 1.5

I just added a bit of baking soda to bring up the TA, but I seriously doubt that slightly low TA is causing ppt.

The only other thing "added" to the tub has been chlorine (with each use), MPS (once), N2 (few days after refill).

Can anyone vertify for me that you get non ppt'ed CA measurements using a Taylor kit and N2?

This is weird!

[anne]

I was told that the reagents are only good for one year.

Page 5 of the Taylor kit manual has a list of criteria for when the reagents are "old" but there are no listed expiration dates. I have stored them properly, and I have none of the signs of age (discoloration, floaties, etc)

I doubt that they only last one year, or we'd all have to be buying a whole new kit every year.

Puzzled......

[Reese]

...I just added a bit of baking soda to bring up the TA, but I seriously doubt that slightly low TA is causing ppt...Can anyone vertify for me that you get non ppt'ed CA measurements using a Taylor kit and N2?

According to the Taylor book, deposit formation (including suspended particles) is an indicator of reagent problems.  It also suggests a one-year turnover, and that colored reagents like the calcium indicator and titrant have shorter shelf life.  FWIW, I don't get ppt readings with Taylor and N2, Cl and MPS, but I fill partially with softened water to get hardness down to about 250.  Even testing tap water (500+ Ca), I don't get ppt.  My hardness reagents are closing in on 2 years old (I seldom test hardness after initial balance) with no problems yet.

I don't have my Taylor wheel handy, but I doubt your water is balanced at those readings.  I'm guessing you need to run your pH and TA pretty low to make up for all that calcium.   If you aren't already, you may want to consider using a stain/scale preventer as part of your routine.

[Pathfinder]

if you havent used up your reagents at least once in a year then there is no need for a taylor kit.   You can buy new bottles usually from your dealer.  I do refills for my regular customers at no charge and $2.50 per reagent for non regulars.

In my previous post i should have stated  even though there are suspended particles in your calcium test  your readings will still be accurate so the reagent should still be of used for about another month until  your tests will not change colour anymore

[anne]

I have used up some of my reagents, but since I only test Ca with each new fill, I have LOTS of those left. If the ppt was due to old reagents, you'd think that my tap water would have had the same issue. I have odd water, I guess. I had a Ca of 600 when I first filled (about a year ago), and was freaking out about deposits. Then on the second or third fill, I had a Ca of less than 50ish, so I actually bought Ca to add! Now I'm back to high. I do use a stain and scale product, even when the Ca has been low, as i think my water is high in other minerals. Had not done that yet with this water, as I was still figuring out if I had high Ca or not. Reese, your post reminded me of the thing I forgot to do!!!!!!!  Argyh! I knew that in the past I had always done "other stuff" then added the N2 later, purposefully delaying the N2. I couldn't remember why I waited on the N2. DUH! It was because I have always added "metal Gone" first. Now I am not sure what to do....starting another thread......

But yes, it seems I need to later my balance a little to make up for the high Ca this time. I'll assume for now that the 450-500 is correct, even if the color change is in ppt, not solution.

Maybe in the future, I'll plan ahead: when I know that a water change should happen soon, I'll start to check my water supply for Ca every few days. When it gets lower, time to use it!!!

I have been so distracted by this kitchen remodeling plan, that other things are slipping through the cracks. My poor tub.

[anne]

The dork-factor is so much worse than I thought. The post I just made somehow made me realize that my Ca right now is *60* not 600. Sigh. I multiplied by 100. I was thinking to myself, "how could I have measured a Ca level in the past of 50, when each increment is 100???" Ah........yeah, having a blonde day. Or week.

This does not change my ppt issue, but it does shange how I'll appraoch water balance!!!!!

   

[Reese]

...i think my water is high in other minerals... It was because I have always added "metal Gone" first....

Now you have identified another potential interference, dissolved metals -- although those should also be present in the tap water.  If I'm still following correctly, you only see the ppt when testing tub water, not tap -- so it seems unlikely that reagent age is the issue -- and since you haven't added metal remover or stain/scale yet, the only difference between tub/tap is temp, N2, ozone, and whatever is left of your Cl and MPS doses.  The only suggestions I have other than trying new Ca reagents at this point are to allow tub water to cool to see if temp is affecting precip (Ca does fall out of solution more at higher temps), to try again after taking the metals out, and also after adding stain/scale.

Please let us know if you find an answer.

[Chad]

Page 5 of the Taylor kit manual has a list of criteria for when the reagents are "old" but there are no listed expiration dates. I have stored them properly, and I have none of the signs of age (discoloration, floaties, etc)

I doubt that they only last one year, or we'd all have to be buying a whole new kit every year.

Puzzled......

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