Chlorine consumption, shocking, testing (maybe not insects)

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Re: Chlorine consumption, shocking, testing (maybe not insec

versstef1 said:
Sorry, guys, for the fact that I keep bumping my own thread. But I'm having a real problem here. Please give me any ideas you have!!!

So, I went ahead and did more testing, using two sets of chemicals. One that was relatively news (well, about a year old, just opened), along with my old "chlorine only" container, not cleaned or anything. I'll call that the old set.

For the other set, I used a brand new container (the one that came with the speed stir), plus brandnew, just received power and titrant. I'll call that the new set.

The spoon was the same for both. The water samples were from the same place, in a fully circulated pool. Some of the tests even used the same exact water which I had gotten in my usual cup. I tried to use the same amount of powder and drop about a second apart. Oh, I also only have one magnet thing, but I rinsed it each time with pool water.

So here is the problem:

Test 1, new set FC 8, CC 0
Test 2, old set FC 10.5, CC .5
Test 3, new set FC 10, CC 0
Test 4, old set FC 11, CC .5

A little while later:
Test 5, new set FC 8 CC 0
Test 6, old set FC 10, CC 0.5
Test 7, new set FC 9, CC less than .5, but a hint of color
Test 8, new set FC 8.5, CC less than .5, but a hint of color

How in the world did I manage to unlearn how to take this simple test? I'm losing my freaking mind. :hammer: :hammer: :hammer:

Thanks for your time.
Click to expand...

Okay, because I'm so sweet I just tested my CL 3 times. Each time the shade of pink was slightly different. Drops required to clear 30,31,32. Each tests scoops of powder were different to, two scoops, but last two I got one good scoop of fine powder vs granus or clumps. You could place powder on hard surface and crush it all with a spoon to get uniform grains.

To me it's within testing error more or less, and doesn't fundamentally change what I'm going to do (lower SWG percent run time) and your tests are similar , not gonna change what you do. I say chill out!
 
Re: Chlorine consumption, shocking, testing (maybe not insec

That is very sweet, thanks! I wanna see it that way (chillaxed), but when the advise is to shock a pool until you have less than 1 PPM in the OCLT, then these differences are well beyond that margin of error.
 
Re: Chlorine consumption, shocking, testing (maybe not insec

harleysilo said:
Have you read this 2 year old thread, good advice in there overnight-free-chlorine-test-margin-of-error-t30903.html?hilit=Free%20chlorine%20margin%20of%20error
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OK, I read that thread. Thank you. It appears from that thread (and mine) that there is no answer for when FAS-DPD test results just won't make sense. That guy had a similar issue, namely not getting the same back to back results. And no one could answer. I guess I could try the damp cloth... But never needed to do that before, so this is odd indeed.
 
Re: Chlorine consumption, shocking, testing (maybe not insec

scott.MI said:
versstef1 said:
Oh, I also only have one magnet thing, but I rinsed it each time with pool water.
Click to expand...
Just to make sure, you are not adding the magnet until after you've measured the correct amount of water?
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Not necessarily. Sometimes I think I put it in first, then add water, then powder. I might even have done magnet, powder, water by accident here and there. Is this significant?
 
Re: Chlorine consumption, shocking, testing (maybe not insec

If the magnet is in first, your using less water than your supposed to (displacement). If you have the magnet in before you fill to the 10ML mark, your not really using 10ML water sample. Someone else had this problem, so for most accurate readings based on their instructions....should start getting your water sample correct first before adding anything. ( magnet or powder)
 
Re: Chlorine consumption, shocking, testing (maybe not insec

Are you holding the bottle vertical and letting the drops drip off the tip?

If you're holding it at an angle and/or squeezing the bottle too hard, that can affect the outcome.
 

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Re: Chlorine consumption, shocking, testing (maybe not insec

Bama Rambler said:
Are you holding the bottle vertical and letting the drops drip off the tip?

If you're holding it at an angle and/or squeezing the bottle too hard, that can affect the outcome.
Click to expand...

I will keep trying to get it right ... I was pretty slack on holding the bottle, but that's because it's always been perfectly fine for over a year, without trying to be perfect like that. What's changed? No idea...
 
Re: Chlorine consumption, shocking, testing (maybe not insec

Sucks... sitting here now with a stop watch to drop at exactly 1 second, holding vertical, wiping off the tip (or not, doesn't even matter), doing everything else by the book - and still cannot get two back-to-back test from the same water sample.

Please, does anyone have any idea what could be the reason?

Edited to say this: I guess now the only other variable could be the amount of powder used... I understand that it would be too little if the sample doesn't turn pink at all. But at what point is it too much powder and what would the consequence be if I used too much? It does seem that I start out with varying shades of pink sometimes, but I always thought that "more within reason" should not matter. How much more does one need for high-level FC testing? Are we talking 3 spoons for FC 20 or more.

Thank you.
 
Re: Chlorine consumption, shocking, testing (maybe not insec

I don't think too much powder affects the test. Too little does though. After you start your speed stir and mix the powder up, stop it and check if you have any undissolved crystals at the bottom. If you have undissolved crystals then you know you have added enough powder. If you don't then add a little more powder. There should always be at least a smidgen of undissolved crystals before you start your drops.
 
Re: Chlorine consumption, shocking, testing (maybe not insec

You may not be reaching the endpoint of the test. Any color change test requires that the last drop added makes absolutely no further color change....none. You then subtract that last drop from the count and that is your result.

The amount of powder used is seldom relevant.

Wiping the dropper tip is only relevant on the TA test.
 
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