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jenmenke
04-29-2006, 07:54 PM
Quick question. I have the 233 test kit. the directions for the Alkalinity test say to add the indicator drops until the liquid turns red. How long does it have to stay red for? Forever? I keep adding it until it stays red for about 5 seconds. But then it goes to a sort of neutral gray color. Do I need to keep adding drops? It seems to make a big difference because it can mean the difference between 140 and 200 for me.

Thank you, and sorry for all my questions this week. I tend to get the pool open, ask a ton of questions to get everything in working order and then disappear for most of the season.
Jennie

waterbear
04-29-2006, 08:03 PM
the endpoint for the test is when the indicator has changed from green to red and adding one more drop of titrant (reagent 3) does not produce any further color change. Don't count that last drop that didn't produce any further color change. The second reagent used in the test is actually the indicator.

jenmenke
04-30-2006, 08:59 AM
Thanks. I understand what you mean. It's just that after I get to that point where there is no further color change, it seems that I screw the top on the bottle and in about that time the water goes back to a color that is somewhere between green and red. Would I go back to adding drops? I guess that's the real dilema I'm having with it.

waterbear
04-30-2006, 11:40 AM
That means there is still alkalinity in the sample that the titrant has not neutralized, Be sure to swirl the vial well after each drop. When the color changes to red and stays there the test is done.

jenmenke
04-30-2006, 02:07 PM
wow. OK. Thanks. that just means my alkalinity is even higher than I thought it was. Glad I asked. I've been doing it wrong for a couple years now.