Discrepancy with recommended Total Alkalinity levels, plus shaking reagents

[TishTash]

1) The Recommended Levels calculator mentions 60-80 being optimal for TA. But the instructions for the TF-100 test kit mention 100-120 being preferable for non-SWG pools. I was just wondering about the discrepancy.

2) It’s never mentioned, so is probably unnecessary, but I’ve seen many people do it: Do reagents need a quick shake before dispensing?

 

[tim5055]

1) The Recommended Levels calculator mentions 60-80 being optimal for TA. But the instructions for the TF-100 test kit mention 100-120 being preferable for non-SWG pools. I was just wondering about the discrepancy.

Our recomendation are ever evolving as we see how pools react to certain levels. This is just one of those areas where documents haven't caught up with changes.

2) It’s never mentioned, so is probably unnecessary, but I’ve seen many people do it: Do reagents need a quick shake before dispensing?

I always do, but I'm not sure if it's necessary. @JoyfulNoise care to opine....

 

[IceShadow]

Non-SWG usually means using pucks / tabs, which are acidic. If you use liquid chlorine, your TA works better at a lower value.

 

[JoyfulNoise]

I always do, but I'm not sure if it's necessary. @JoyfulNoise care to opine....

It is wrong, in most instances, to vigorously shake any of the reagents. A simple gentle inversion of the cylinder or hand swirl is more than enough to mix most of the reagents. You are not causing the chemical reactions to work any better by shaking but you are entraining air bubbles, causing outgassing, and possibly inducing foaming by shaking vigorously. There is simply no need to do it and the instructions in the kit that say "shake" ought to be changed to "mix". If you read the Taylor instructions for any of their tests on their website, they never, as far as I have seen in their pool testing chemicals, use the word "shake", it is always "mix" or "swirl to mix".

Another reason to purchase and use a SpeedStir. The rate of swirling caused by the magnetic stir bar is more than adequate to get rapid mixing and quick results.

 

[TishTash]

It is wrong, in most instances, to vigorously shake any of the reagents. A simple gentle inversion of the cylinder or hand swirl is more than enough to mix most of the reagents....

Another reason to purchase and use a SpeedStir. The rate of swirling caused by the magnetic stir bar is more than adequate to get rapid mixing and quick results.

Agreed with your points, but I think you misunderstood: The original question was referring to agitating the reagents in the drop bottles before dispensing.

Incidentally, one of the (few) pet peeves I have about the SpeedStir is that it’s more difficult ascertaining whether there’s still any light shade of pink remaining, vs inspecting the sample while it’s still.

 

[IceShadow]

What would shaking the bottles help? They’re all consistent chemicals without anything in them that could precipitate out or require reintegration. And adding bubbles that could interfere with droplet size seems unwise.

 

[TishTash]

What would shaking the bottles help? They’re all consistent chemicals without anything in them that could precipitate out or require reintegration. And adding bubbles that could interfere with droplet size seems unwise.

I suppose that’s the answer I was looking for, i.e., whether any reagents had components capable of settling. I just noticed many demonstrators doing it as almost a habit. Thanks for setting me straight!

 

[trophft]

Agreed with your points, but I think you misunderstood: The original question was referring to agitating the reagents in the drop bottles before dispensing.

Incidentally, one of the (few) pet peeves I have about the SpeedStir is that it’s more difficult ascertaining whether there’s still any light shade of pink remaining, vs inspecting the sample while it’s still.

Ditto, I thought I didn't have any pink during chlorine test, and when i removed the cylinder from my speedstir and turned off the light etc. i detected a hint of pink...

 

[tim5055]

Ditto, I thought I didn't have any pink during chlorine test, and when i removed the cylinder from my speedstir and turned off the light etc. i detected a hint of pink...

Be careful, during the chlorine test once it's done the pink will slowly return. Stop when it's clear and don't worry the pink comes back.

 

[trophft]

Be careful, during the chlorine test once it's done the pink will slowly return. Stop when it's clear and don't worry the pink comes back.

tim, you mean once you start adding the drops?
I'm talking about step one when i put a heaping scoop of R-0870 powder in 10mls. I thought it stayed clear, but when i turned off the speedstir and removed the cylinder i could see a hint of pink. The brightness of the light seems to drown out the hint of color...

 

[tim5055]

tim, you mean once you start adding the drops?
I'm talking about step one when i put a heaping scoop of R-0870 powder in 10mls. I thought it stayed clear, but when i turned off the speedstir and removed the cylinder i could see a hint of pink. The brightness of the light seems to drown out the hint of color...

When you are done adding drops. Once it goes clear, you are done. As it sits after that point the pink will return.

If it's clear when you add the powder you have no chlorine.

 

[trophft]

When you are done adding drops. Once it goes clear, you are done. As it sits after that point the pink will return.

If it's clear when you add the powder you have no chlorine.

Yes sir, got it thanks! Going to add 38 oz. of 10% chlorine right now (thanks to TFP PoolMath!)
Man I love this TFP community!!!

 

[trophft]

When you are done adding drops. Once it goes clear, you are done. As it sits after that point the pink will return.

If it's clear when you add the powder you have no chlorine.

Tonight's readings
FC 3.5 (took 7 drops of R-0871 to turn it clear)
CC 0.5 (TC 4)
pH 7.5
TA 80
CH 300 (11 drops turned it blue, but then back to pink...12th drop kept it blue)
CYA 30 (can still faintly see the black dot)
Water Temp 92

Finally think I'm getting the hang of it!

 

[TishTash]

Ditto, I thought I didn't have any pink during chlorine test, and when i removed the cylinder from my speedstir and turned off the light etc. i detected a hint of pink...

I should probably give the SpeedStir backlight another try with the FAS/DPD test. It's just that after X number of drops, I would think it’s clear, but then immediately after shutting off the light, I noticed it was still pink (as opposed to turning pink over time). Retesting without the light (either on the SpeedStir or manually swirling) confirmed the extra drop. So too bright a light can possibly mask a remaining pink tinge.

 

[TishTash]

In response to an incorrectly placed thread:

I've noticed this as well and I've learned that if you view the sample from the side rather than top-down, you can see the pink better. Once its clear from the side then I don't see any pink after shutting off the light. FWIW.

It also helps to have a white background, it goes without saying....

 

[HermanTX]

Agreed with your points, but I think you misunderstood: The original question was referring to agitating the reagents in the drop bottles before dispensing.

Incidentally, one of the (few) pet peeves I have about the SpeedStir is that it’s more difficult ascertaining whether there’s still any light shade of pink remaining, vs inspecting the sample while it’s still.

When using the speed stir, I watch for the fluid to go clear, then I pick the vial up off the speed stir, hold it to light and confirm. If I still see a faint pink, I put it back on speed stir and add 1 more drop and then pick up again to confirm. That process is less than 5 secs.

I agree that if you let the vial sit for a minute or so, it may return a faint pink, however, as soon as I see clear, I dump the fluid in my waste cup, rinse the vial, dry it and store it along with its dedicated stirrer.

 

[TishTash]

When using the speed stir, I watch for the fluid to go clear, then I pick the vial up off the speed stir, hold it to light and confirm. If I still see a faint pink, I put it back on speed stir and add 1 more drop and then pick up again to confirm.

That's a actually good way to cover one’s bases.