ColorpHast 9590-3 Test Strips, 0-14 pH (Box of 100)

I contacted the company personally to tell me how to accurately use these test strips since it doesn't come with directions and what little was written on the package was a foreign language. Here's what they said.....General Procedure for the use of colorpHast Test Strips: This procedure is also printed on the colorchart label.1. Remove the strip from the box.2. Immerse the reaction zone of the strip into the solution for approximately 3-5 seconds oruntil there is no further color change.**3. Remove the strip from the solution, wiping the strip along the edge of the vessel toremove excess liquid from the strip.4. Compare the reaction zones to the color chart on the box holding the strip to the top ofthe box with the reaction zones to the bottom of the box.5. Record the results of the closest matching color to the strip.** For weakly buffered solutions, an extended period of time may be necessary. In these cases, immerse strip until there isno further color change (1-10 minutes). Because the indicator is covalently bound to the colorpHast® strip, the test strip maybe immersed in the solution for longer periods of time if necessary.I tested the strips using vinegar and definitely got an acidic reaction. I was getting concerned because pretty much every time I tested my dogs urine I was getting the same reading. So far I think they're accurate and they surely are easy to use!

As an Esthetics Instructor, I was looking for inexpensive 0-14 pH testing strips to use in the classroom. At 12 cents a strip, this was a great deal. The value was even better when I began to use them. The pH of the products we use on our skin is very important. Sometimes we want to raise or lower the pH, but we also want to make sure we are following that with the proper product to then neutralize the skins pH. Using these strips makes for a great visual aid and makes teaching (for me, and understanding for them) so much more effective. I have used them on many products I already knew the pH of, and every time they have been accurate. The no-bleed factor is great too, as I feel comfortable dipping the strips right into my product. So far, this product hasn't let me down. I will definitely be sticking with this product when it's time to reorder.

I wasn't impressed with this product. There were no written directions, leaving me a bit confused as to how to use them, namely, how far to dip them into the solution, etc. The pictures on the box helped me figure it out, but I am still unsure as to whether I am using them correctly. My biggest complaint is that it is hard to tell exactly what the ph is because the color charts are not that unique between, say 3 and 4. You can definitely tell ph 1 from ph 3, but telling 1 from 2 or 3 from 4 is a bit more ambiguous. Also, there is no way to tell if the solution is 4.1 or 4.9. If you don't need too accurate of readings, these should be fine for you, although they're a bit expensive. Overall, though, not the best product, either go for a meter, or go for the cheap strips... in my opinion, these aren't accurate enough to justify the price.

Great product and very convenient for initial testing in the field. I tried the strips and checked them against my 'meter' and found the pH values to be quite consistent.

Great

Nothing to dislike.

I bought these for home brewing (specifically, measuring mash pH, which is typically 5.2-5.8) since my current stock of ColorpHast strips is several years old. I also own an electronic meter ($90) and calibrating solutions. For the last 4 uses, I've checked pH with both these strips and my electronic meter (calibrated before and after each use) and found that these ColorpHast strips read low by: 0.4, 0.6, 0.4, and 0.4. Looks like they are neither accurate nor precise, which makes them useless when you need to be within a couple tenths. Current thinking in the homebrew community is that these generally read low by 0.2-0.3, so my experience is similar (but worse) than some others.I've seen little difference from the strips that are several years old compared to these new strips. Typically about 0.1 difference. So don't throw them in the garbage because they're old, but rather because they're inaccurate.

These pH strips work really well. They verify to be accurate, do not bleed, and are easy to read.