Re: stabilizer and hardner

Originally Posted by
CarlD
How about YOU get your facts straight? So far you've been perpetuating the usual pool store nonsense and mis-information that we have been trying to help people avoid the pitfalls of.
Test strips are notorious for varying from strip to strip--that's not a precision issue, that's a reliability issue--and it is QUITE correct to say that an unreliable testing system is NOT accurate.
I have both the LaMotte and Hach strips--the good ones complete with CYA tests and fresh this season (and every season), and I can tell you flat out from LOTS of experience that they are NOT accurate. ONLY the FC test is fairly consistent and reliable. TC ALWAYS reads lower than FC, which is impossible, so how is THAT accurate?
pH is unreadable. CYA isn't even CLOSE to accurate. and total hardness? Meaningless.
I use strips because I know what they ARE good for, and what they are NOT. But I always prefer drop testing when I have time--and I usually don't--so the strip gives me a CLUE as to what's going on.
I also use 3 different FAS-DPD kits (including Ben's), several OTO kits, a DPD kit, and the ubiquitous WalMart 5 Way Test kit.
I've tried various strips and ONLY these two are worth more than used oil filters. The rest are total garbage.
Carl,
Once again we agree to disagree (but if you read what I write below you will find we are on the same page as far as the important things concerning test strips). I have to agree with Ugaguard that strip are accurate but not precise! (I know, it's semantics....but it's true)
Test strips are accurate in that the reagents will react and produce the proper color when given the correct developement time. They are not precise because they are almost impossible to read and if you let them develop too long the colors will change! Also the graduations on the color charts are just too wide for any practical info on the pool chemistry. This is why they are not good for more than a quick check to see if you are in the ballpark! The CYA test on the LaMotte is next to usless and the Aquacheck test does not give you a precise reading at all! The graduation of the comparator is just too large. I also have several types of test strips..I find the LaMotte 6 way are more consistant but harder to read than the aquacheck, and more time sensitive as to when to read them. The LaMotte 5 way are totally useless! (they don't use the same reagents for some of the same tests!)
The ONLY test strip that I have found that is consistant and easy to read is the AquaCheck White salt test strip, which I have found to be within 150 ppm or so of a calibrated salt meter. It is based on the same chormate/silver nitrate chemisty as the drop test and each bottle is individually calibrated.
Last edited by waterbear; 07-07-2006 at 11:15 PM.
Retired pool store and commercial pool maintenance guy.
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