Chemical Drop Sizes

saml

Well-known member
Jun 4, 2008
51
Near Knoxville TN
#1
I finally got me a test kit with titrants/drops. On the TA test I get 180 where as two different test strips indicate ~120. It appears the kit's TA drops are smaller than most others. Also I read somewhere in another forum that I should wait 20-30 seconds between drops on the CH test. Does that sound right? I know the first one I tried I got 400 but the strips were 250. I slowed down some and tried to get bigger drops cause they were really small and got 240. Is there any suggestions for my techniques and is there someway to verify proper drop size?

Thanks a bunch for any help.
 

JasonLion

TFP Expert
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LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
Don't be surprised if the new test kit gives different results than the test strips. Almost certainly the test strips were wrong and the new test kit is right.

On the CH test you need to keep swirling the vial for 20 to 30 seconds to mix throughly between drops, not just wait.

There have been dropper tips that were the wrong size in the past, but that is very rare. I suspect you just need a little practice with the kit and everything will be repeatable.
 
G
#3
To get a uniform drop size hold the dropper bottle inverted and not tilted to one side. Let the drop form one drop at a time and don't try and squeeze out the drops too fast. Sometimes static charges can affect drop size. Wiping the dropper tip with a damp tissue between each drop will prevent this from happening.
 

saml

Well-known member
Jun 4, 2008
51
Near Knoxville TN
#4
Has anyone ever ran a straight pin through the bottle tip to ensure its completely open? Also, that's interesting about the static charge. On the CH test the reagent appeared to fall diagonally. I thought this is weird. Perhaps its not so unusual. Thanks for the tips. (No pun intended)
 

KenJ

LifeTime Supporter
May 5, 2008
27
Glenside, PA
#5
I ran into a similar issue and in "talking" to Dave it may be that he had some tips for the bottles with holes that were smaller than they should have been. I am getting a tiny stream instead of drops. If you have some other bottles aroung try switching the tips - I'll be trying this tonight.
 

skinman

LifeTime Supporter
May 29, 2008
38
SE Michigan
#7
My TA drop size is the same as saml. They are about half the size of the other tests. Is this normal or are my tests invalid?

I need to know because my first test from the tanker water for TA was 380.

I dropped the pH and have been aerating like a school of pirhana on a side of beef.
 

KenJ

LifeTime Supporter
May 5, 2008
27
Glenside, PA
#8
Gang -

If you've gotten a test kit from Dave, aka duraleigh, recentlythen please wait to hear from him on this thread before adding anything to your pool based on the resuslts of the new test kits. I know for a fact that my R009 bottle has the wrong tip on it! I don't want to speak for Dave but I don't want to see people really foul up their water.
 

saml

Well-known member
Jun 4, 2008
51
Near Knoxville TN
#10
My kit is a TF100 as well, so before I run out and drop an acid ball or any TA adjustments I'll hold out for Dave. I did notice however that on a test I just did to compare with the strips, the strip indicated about 120 at the 15 second mark but after another 10 seconds or so it was at 180 which I had a 190 on my latest kit test where I swirled 15-20 seconds between drops and held the bottle vertically while letting the drop form. All other strip numbers looked in line with the test kit.

Thanks for all the responses. It's good not to be alone in my pool war in which I have lost most of the battles but not the war.
 

duraleigh

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Apr 1, 2007
31,271
Sebring, Florida
#11
Well, it appears that somehow our supplier has mixed in a few wrong tips with the correct ones. Let's first talk about how you can tell.

If you have the correct tip, all the reagents will come out of the bottle in such a way that you can count each drop. Now you could get a little careless and apply too much pressure to the bottle but, generally, they should stay seperate and countable.

If you have the wrong tip, it is incredibly difficult to contol the drop rate. The drops tend to be small and almost "shoot" out of the bottle....it's very difficult to make the drops uniform. They even seem to come out of the tip at an odd angle sometimes.

The biggest giveaway that you have the wrong tip is that your other reagents will be obviously easier to control. So if you have 5 that are reasonably consistent and one that gives you a fit, you obviously have one bad tip.

Here's a temporary solution. Simply remove one of the good tips from any of the other reagents by bending it over at a 90 degree angle to vertical....it'll snap right out. Now rinse that dropper tip thoroughly in tap water, inside and out and replace the offending tip with this newly rinsed one. (all the reagents are water soluble)

This will allow you to perform any test you may have to do, until we can get you your new dropper tips.

Here's the permanent solution, after you have determined you have a bid tip or tips, please send an email to Tftestkits@hughes.net and tell me how many tips you need. Please include your MAILING address as these will go out first class mail. We'll get them right out to you the same day we get your email if we get it by 2:00pm.

The tips are virtually identical (the hole is smaller on the wrong ones but it's difficult to tell....use the performance above as the determining factor to decide if you have a bad one) but we know what to look for here so we'll be examining them carefully to insure that everyone's is correct from here.

Sorry for the inconvenience this has caused you but let me know and we'll get it corrected.
 

skinman

LifeTime Supporter
May 29, 2008
38
SE Michigan
#13
Here's a temporary solution. Simply remove one of the good tips from any of the other reagents by bending it over at a 90 degree angle to vertical....it'll snap right out. Now rinse that dropper tip thoroughly in tap water, inside and out and replace the offending tip with this newly rinsed one. (they're all water soluable)
How much can we rinse the tip before it dissolves? :shock:

Sorry, I'm new and shouldn't do that. :hammer:

No harm done. This will make my TA readings lower but my kids will miss the water spray I made to aerate.
 

Butterfly

TFP Expert
LifeTime Supporter
May 31, 2007
10,045
South Carolina
#16
Dave, um, what was it that The Mermaid Queen :thequeen: said about your elves?........those little guys seem to be on the warpath about something........you might need to sneak out to the barn and peek into the window to see what they're up to .... :twisted:

p.s. pack a pistol
 

skinman

LifeTime Supporter
May 29, 2008
38
SE Michigan
#18
I've got one that seems to be the smaller tip from the symptoms you describe and the control of the drops compared to the others.
I'm going to swap tips as you suggested to make sure. I'm guessing my reading for TA may be slightly different. Thank you for the response and solution. I love this test kit. :party: