General Hydroponics Ph Test Kit, 1 oz

Works great for adjusting ph & lasts a long time.

(Note: Similar review under the Biopharm version as this is a comparison) A lot of people struggle with measuring pH and there are a lot of potential reasons such as pH pen drift, incorrect or inconsistent calibrations. I've sure tried to kill more than my share of plants chasing what I thought was a correct pH. I've also tried the strips, but old eyes, slight color blindness, and tiny squares don't play well together. So, I've moved to the pH drop tests and the plants are loving the correct range. I had initially bought the Biopharm 5.0-8.0 range drops and was comparing the results against the Biophbarm printed label. It was doing ok, but I was still getting some leaf issues here and there. Most of the variance was me not being able to compare the difference in the results to the label colors well enough. As I was looking for better measuring, I came across an image in the product description that I missed the first time around. This was the last image in the product details and showed 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, and 8.0 pH color spectrum results that were perfect for me to compare against. I added that image to my phone and use it to set my pH on target every time. MUCH better than the printed label. Based on now being able to dial in my pH on target every time, I'm giving this a 5.0 since it's much easier with the Biopharm image. I have attached that image to this review in case it ever disappears from the product page. While looking at the reviews for test drops, I saw a number of concerns about the General Hydroponics using needing to use 3-5 drops with the Biopharm using only 3 drops. So, I bought the GH as well to compare and found that both the General Hydroponics and Biopharm versions performed equally well - as long as you ignore the printed label (see 3/5 drop comparison image). The General Hydroponics printed label colors are colorful, but were less than useful to me. The Biopharm label wasn't as far off as the GH label, but both add in additional 4-color printing issues. So, even though I thought I was comparing correctly against the label, both the label and my pen were off (see pen measurement pics) and the plants suffered because I believed the pen more. When I did my direct head to head test of the General Hydroponics and Biopharm against the same water source, I found the most equally consistent comparison to be 4 drops of the General Hydroponics and 3 drops of the Biopharm (see 3/5 drop comparison image). I've included an image of the 3 to 5 drop test. You can see the General Hydroponics is just a little darker but is the same hue. Remember that you are looking for that difference in hue, not the difference in lighter/darker. The lightness or darkness of the color is a result of how concentrated the indicator agent is - nothing more [more or less]. Of course, you could use more or less drops if that helps you tell the difference. I am 5-star happy with both the General Hydroponics and Biopharm. You can see how far off my ph pen was in the 3rd image. Definitely time to recalibrate or replace my pen. tl;dr: Both the General Hydroponics and Biopharm tested equally well for me. Ignore how light/dark the results are; it's irrelevant. Compare against the hue (shift from red<->green). Use the pH color spectrum image instead of what is on the bottle.

It works

These are way more reliable than any meter you can buy.

Simple to use and understand. Comes with no instructions except on the bottle label. Simply fill vial half full of water to test, add 4 or 5 drops of ph tester, shake and match the color to the color chart on the bottle. Safe levels indicated clearly by color. Tested our tap water from 2 sinks, and color matched perfectly and indicated just slightly outside the boundaries of good levels. Tested 2 water filters, one was older and attached to sink and had just crapped out - which indicated was making water worse than from tap without the filter, and the other filter was new and in our refrigerator, which indicated was making water better. Finally, tested a bottled water from store, and indicated was equally as safe as our new refrigerator filtered water. Retested tap water and maintained slightly outside good level. Retested sink old filtered water, and maintained making water worse. Threw away old sink filter, which confirmed our suspicion that it had definitely crapped out. Happy to have our family drinking only good water from either the new filter in our fridge or store bottled water. Peace of mind for us all thanks to this wonderful easy to use product!

Good product, accurate.

Works well

The best arsenal I keep for correcting water Ph levels! GH delivers a very accurate and very dependable product every time. Highly recommend.

Great product. Gave me accurate ph tests. Very easy to use and dependable results. Sometimes keeping it simple just works.

Gh has always been a quality ptoduct but this item is severely overpriced on here..3x the cost of a grow store.

Much better then ph pens perfect everytime, delivery took waaaay too long Thats on Amazon, as a prime member I shouldn't be waiting 10 days, but product is outstanding I highly recommend it, general hydroponics is owned by Monsanto, i will order it again

Works good , my color is off on the 6.5 measurement, but can figure it out.

Before this i had purchased 3 ph tester pens, and all 3 will not allow be to properly calibrate it. Spend hours trying to calibrate them with no success. Decided to give this a shot instead, and it was very easy to use. Don't waste your money on those cheap ph meters, they only have a 50% chance of them working. Or in my case, none of them worked for me.