duraleigh said:
4jaw,
Regardless of the outcome of the test strip results, there is simply too much evidence over the years to do anything but conclude that test strips are inadequate for the precision we talk about here on this forum.
Of course, I have a dog in the the fight but long, long before TFTestkits existed, it was apparent to me that test strips were inadequate to effectively manage your pool. There are simply too many posts on this and other forums that demonstrate the inadequacy of strips.
Well that really is the question isn't it...precision.
At what precision do I need to measure things like FC and PH?
For my pool with a CYA level of 55 anything between 5 and 10 for FC is close enough because tomorrow it will be two points below that.
For PH all I need to know is if its between 7.4 to 7.6 for me to be happy.
From my experience knowing the volume of the pool was far more important to proper dosing than what I seen in the drop tests, I needed to know what the levels were for sure...but what counted was how much to add to correct to achieve the proper result.
Do I care if my FC is 6 or 7? No, its within safe range for my pool...and tomorrow I will add the appropriate amount to account for normal daily loss. If I let the FC drop to 5 am I going to freak out? Of course not, I will add some after we are finished swimming for the day and correct it to midrange of 7 at the end of the day...or if I am lazy I will raise it to 10 so by the end of tomorrow it will be 8.
I have options.
Strips are an option thats all I am saying, they aren't the holy grail but they aren't the bogeyman either if you know what you are doing.
BTW I just tried five of the strips completely unscientifically and the results matched my DPD drop test exactly...PH, FC, TA were all what I would expect them to be and these strips confirmed what I already knew. I am still not satisfied with this test kit because the FC range only tells you if its between 5 and 10, I would prefer a two part strip that tells me the FC level more closely...I could care less what my TA is since I only correct it twice a year and it hardly moves. The PH color on the strip was bang on match for my DPD drop test, I tried 5 strips and layed them side by side and they all agreed with each other. PH was 7.5...and thats all I needed to know. At 5 cents a strip, thats cheap knowledge I can now trust.
So how is this bad? Am I able to superchlorinate using a strip (I never have to do that anyway). No!
Am I able to check my CYA with this strip? Who cares it hardly moves over three months.
Is my TA within the range of 80-120? Yep, my DPD drop kit tells me its 100 exactly but who cares if it only needs correcting twice a year.
Using an "indicator strip" requires knowledge of the scope and purpose of the device which is where 99% of the users of the strips are failing in my opinion, in this case it is a verification tool that takes less than 5 seconds to administer and read. An indicator strip failure requires intervention and this is where my DPD test kit comes in, in medicine thats when they call me to find out whats wrong and repair or adjust to find out the problem.
I just think making blanket statements that strips are useless or give false readings without scientific first hand proof is misleading, I see a purpose and use for them in my pool maintenance regimen and will continue to look for the perfect one that fits my needs.
