LaMotte Alkalinity, i'm dumb

[nava405]

alight just got test my water with LaMotte Alkalinity test kit, and i have no idea what it means. i got 116ppm which = to what DKH ???

 

[gcarroll]

6.5 DKH

 

[jdieck]

50 ppm = 1 meq/lt
17.86 ppm = 1 dKh

so divide by 50 to get meq/lt or by 17.86 to get dKh

 

[nava405]

116 / 17.9 right ? i just test it again, i got 136ppm which is about 7.5 dkh.. while my the other test kit read 8.5-9 DKH...and i have been dosing kh buffer for 3 days...don't know which one to trust now.

 

[F35-Joint Strike Fighter]

this will help:

http://www.saltyzoo.com/SaltyCalcs/AlkConv.php

 

[nava405]

WTH.. i just test it 2 more times.. and i got 150ppm now..

 

[jdieck]

When using tritration remember that once you reach the point were you think the color has changed you shall continue dripping tritrant and insure that in effect the color does not change any more. I have the impression you might be stopping tritration too soon before the color has completely changed.
I trust the Alkalinity kit of LaMotte over any other one I have tested. It is one if not the best out there.

 

[nava405]

<a href=showthread.php?s=&postid=10331003#post10331003 target=_blank>Originally posted</a> by jdieck
When using tritration remember that once you reach the point were you think the color has changed you shall continue dripping tritrant and insure that in effect the color does not change any more. I have the impression you might be stopping tritration too soon before the color has completely changed.
I trust the Alkalinity kit of LaMotte over any other one I have tested. It is one if not the best out there.

so you mean that i should keep dripping it till right before it changes to the color to red which is the over drip point?

 

[slavearm]

I have the EXACT same question... I just started using the LAmotte kit also.

 

[jdieck]

The color will start to change from green blue to purple and from purple to purple-redish and the final comes when redish becomes clearer starting to get a bit of orange with no traces of any purplish in it. That is the end point.
The best way for first users is to at least once make a tritration , teke a reading at the point were you think is the end then continue adding drops until the color does not significantly change any longer that way you will determine the final color for the subsequent testing.

 

[nava405]

<a href=showthread.php?s=&postid=10332021#post10332021 target=_blank>Originally posted</a> by jdieck
The color will start to change from green blue to purple and from purple to purple-redish and the final comes when redish becomes clearer starting to get a bit of orange with no traces of any purplish in it. That is the end point.
The best way for first users is to at least once make a tritration , teke a reading at the point were you think is the end then continue adding drops until the color does not significantly change any longer that way you will determine the final color for the subsequent testing.

i thought once your see orange or red that means you pass the end point already ?

i think it's big different if you stop at purple which is endpoint or right before it turns orange/red...that's maybe 10ppm there ?

so which one is correct ? stop when the purple shows and few more drops? or right before it turns orange/red ?

 

[jdieck]

When the color no longer changes that is once changes to orange red.

 

[nava405]

alright.. i test the alkalinity again today...and i got 136ppm which is when the color kinda stays in purple. but i got 145ppm right before it turns orange..so which one is correct ??

 

[jdieck]

one more drop after 145 so about 155 ppm

 

[nava405]

err....alright, so you saying that on the instruction tells you to stop when it hits the end point is incorrect ?

 

[jdieck]

If I remember the instructions it mentions also that the end point is when there is no longer change. When I caompared the results withing three different kits that is were it was more compatibility.

 

[gcarroll]

According to instructions, which I advise anyone who is using a Lamotte test kit read, the end point is purple (matching the color on the card included in the test kit. Is everyone just changing over to Lamotte kits and using their instructions from their old Salifert kits?

 

[GTR]

:lol:

SteveU

 

[nava405]

<a href=showthread.php?s=&postid=10365747#post10365747 target=_blank>Originally posted</a> by gcarroll
According to instructions, which I advise anyone who is using a Lamotte test kit read, the end point is purple (matching the color on the card included in the test kit. Is everyone just changing over to Lamotte kits and using their instructions from their old Salifert kits?

that's what i thought, but i read low doing that way and i m bad at color matching...

i'm not sure if "matching the end point color" is more accurate, or jdieck's way, which 1 drop after orange/red....

 

[slavearm]

I read the LaMotte instructions, which really blow I might add. I even went to the website and called them. They said you have to make sure it matches the card exactly. A lot of help that was.

Here is a link to Scientific Titration. [url[http://en.wikipedia.org/wiki/Titration[/url]
Look at the third or fourth paragraph. It would seem to still leave us in the dark as with this kit there is some play between when it first starts to change color and the point at which there is excess titrant in the solution.

The question then becomes, which one is the correct reading? I mean there is about 3-4 dKh play between the two points.