A Question about measuring Ph

[Bill_Stevenson]

I am using test strips for testing my water and just for fun I bought a different brand to double check for accuracy.  The two brands give quite different results for Ph.  In an attempt to resolve the discrepency I took a water sample to the local shop where they check it with some other kinds of strips and a computer gizmo, but once again the result was different readings for Ph.  Since I took the measurements at home and drew the sample within minutes of each other the three results have me scatching my head.  FWIW, the spread is 6.9 to 8.4.  

From this forum I have gleaned that the liquid test kits are only reliable if the chemicals are fresh, it begs a question:  What is the most accurate, reliable, and practical way to measure Ph?

Thanks,

Bill

[wmccall]

The liquid test kits work best for me.

Once common rookie mistake though is to get a reading,  add chemicals to make a change, check again in an hour, and add more.  Allow at least 24 hours after adding checmicals to check again.

I could never decide on a single reading from the test strips.

[Winnsome]

I had the same problem checking our PH levels.  I finally invested in a electronic PH meter that is calibrated to +- .01    Sure takes the guess work out of it.  A little pricey ($100 or so) but sure makes it easy.  I have found the Taylor Test Kit I bought from Doc's site however gives very close readings to the electronic meter.  And buying from Doc you do get the freshest chemicals.

[wmccall]

I had the same problem checking our PH levels.  I finally invested in a electronic PH meter that is calibrated to +- .01    Sure takes the guess work out of it.  A little pricey ($100 or so) but sure makes it easy.  I have found the Taylor Test Kit I bought from Doc's site however gives very close readings to the electronic meter.  And buying from Doc you do get the freshest chemicals.

I wonder how often it would need calibrating?

[Winnsome]

Mine has a refillable sensor, comes with a new solution to refill the sensor.  It also has a buffer solution to calibrate, one is PH 4 and one is PH 7.  The unit tells you when to recalibrate and also tells you when to refill the sensor.  Comes with a year warranty, and I've been told with the refillable sensors, they shouldn't wear out.  Worst case, a new sensor is around $40.    I have used it since October 04, checking once a day for PH levels.  Unit has told me to recalibrate twice, never has said to refill yet.  I have double checked it with a $1000 unit i have access to, and they have been perfect every time so far.  I just love electronic gadgets.  When I went to college, we used slide rules.  So i have just loved the new technology ever since.

[h20bill]

test strips are a kinda like training wheels, if you really want accurate results get a taylor test kit. remember to always test for chlorine or bromine first. if more than 2 ppm of chlorine is present, you must add extra drops of thiosulfate to your ph test vial sample water to get an accurate reading of ph. If you don't, then your ph color will become lightened or bleached out by the sanitizer. try taking two ph samples that have high chlorine and
try testing one without thiolsulfate and one with. you will see that you get two different measurements. it's hard to get accurate ph and alkalinity results when high sanitizer is present. also remember to correct total alkalinity first 90-130 ppm before correcting PH

[Bill_Stevenson]

Tell me more about the electronic gizmo.  What is it called?  Who makes it?  Where can I buy one?  Is it worth it?

As far as the Taylor kit is concerned, for those that are using it, how often do you buy fresh chems?  How can you be sure the chems are fresh?  Besides Ph, what does it measure?  

Thanks,

Bill

[Winnsome]

They are called a PH Meter.  you can buy various brands, makes, and models.  I saw them ranging from $50 to $1000     Mine is made by Extech Corp.  A USA company.  Go to http//extech.com and look up the PH meter side.  LaMotte Corp. who makes most of the test strips for different company's, also sells the Extech PH Meter under their own name.  Doesn't seem to care where you buy it, it's the same price everywhere.  $99 for the refillable one and $89 for the unrefillable one.  If you buy one, get a buffering solution of PH 4 and PH 7 to calibrate the units.

The Taylor Test kit K 2005 series, tests everything.  Go to Taylortechnologies.com and read what it does, then buy it from Doc's site here.  Doc takes pretty care of making his testing equipment the freshest you can buy.  

[Lori]

Tell me more about the electronic gizmo.  What is it called?  Who makes it?  Where can I buy one?  Is it worth it?

As far as the Taylor kit is concerned, for those that are using it, how often do you buy fresh chems?  How can you be sure the chems are fresh?  Besides Ph, what does it measure?  

Thanks,

Bill

It is my understanding the reagents last (generally) about a year.  I just re-stocked my reagents from Doc.  Bought my original kit from him, too!  www.rhtubs.com  That is where I learned about the reagent kits!