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Availability:
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Arrives
Saturday, Mar 28
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Size: Kit
Features
- General Hydroponics pH Control Kit contains everything you need to measure pH levels of your hydroponic grow reservoirs
- RELIABLE RESULTS: The streamlined testing system delivers fast, accurate, and easy-to read results every time
- ALL-IN-ONE KIT: Includes 8 oz. General Hydroponics pH Up Liquid, 8 oz. General Hydroponics pH Down Liquid, 1 oz. Test Indicator, test tube, an eyedropper, and a pH level chart
- THE PREFERRED WAY OF TESTING pH: Seasoned growers prefer our pH Test Kit to expensive electronic meters because of its reliability and ease-of- use
- EASY TO USE: To use, simply fill a test tube halfway with nutrients, add a few drops of pH test indicator, and observe the coloration of the liquid; recommended pH for most plants is 5.5 to 6.5
Description
General Hydroponics® pH Control Kit accurately and efficiently measures the pH levels of your nutrient solutions, grow reservoirs, and the rest of your hydroponic system. pH control is essential for vigorous plant growth. Nutrient solution pH that is too high (basic), or too low (acidic), cannot be properly absorbed by plant roots. Incorrect nutrient solution pH can cause slow growth, sickly plants, and low yields. But General Hydroponics® pH Control Kit is here to help. The kit contains everything you need to test pH levels and make adjustments so you can easily monitor and manage pH levels throughout your hydroponic grow. Kit includes: 8 oz. pH Up, 8 oz. pH Down, 1 oz. test indicator, a test tube, eyedropper, and pH Level Chart. To maximize plant growth, the pH level of your nutrients should be slightly acidic. Experienced growers consider the ideal pH for most crops to fall between 5. 5 and 6. 5.
Product Dimensions: 1 x 1 x 1 inches
Item Weight: 1.5 pounds
Department: Unisex-Adult
Manufacturer: Hawthorne Hydroponics, LLC
Item model number: HGC722080
Is Discontinued By Manufacturer: No
Date First Available: April 4, 2004
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Saturday, Mar 28
This item is non-returnable:
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
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Top Amazon Reviews
Size: Kit
This product does exactly what it says it does! efficiently too! this product is 3 bottles pH-up, pH-down and a pH test solution. (also comes with a vial to conduct the pH testing in AND a pipette which I thought was great, I ended up getting on before I opened the package assuming they did not provide one, but General Hydroponics really gives you everything you need to open the package and do testing RIGHT AWAY!) I tested this on my hydroponic system with a calibrated pH meter hehe.....I wanted to know how accurate the test solution is. The test solution runs on a color scale, acidic being pink basic being dark green. The scale is located ON THE BOTTLE! so you never will lose it. As far as my basic testing concluded, the test solution is accurate; the color changes are visibly recognizable and comparable to the provided scale. 6.0 is yellow, 7.0 is green, and both of these matched my pH meter (in approximation, don't expect to perfectly get a 6.3 or something, this test kit is intended for keeping pH in a safe range, you could play with it and get exactly what pH you want with the assistance of a pH meter but I am judging this based on if a user DID NOT have access to a pH meter going on the test solution only.) The acid solution is very effective, which is nice, you don't want to use a lot of product to achieve results and end up being in need of more solution spending more $$$. I suggest using this 1-3 drop at a time, waiting 20 mins or so based on water flow and size of your container, and doing another test. Don't over do it, always undershoot what you are aiming for; you will save product and also prevent too acid/basic solution......just be patient, eventually you will understand the power of the acid/base solutions and wont even have to second guess if you put too much in or not. All in all, this is a must for a hobby hydroponic gardener or even a professional. Having a pH meter is nice, but some times the calibration may be off and having another testing method as provided in this kit is a good safety. I enjoy testing my solutions BOTH with the meter and the test solution because I know with out a doubt if my solution is within the correct pH range. This will last probably a year or even more depending on how big your system is. Just use sparingly and maybe play with the testing solution with known known acid/base solutions so you can take not of what the ACTUAL color of the liquid will look like in correspondence with the pH. Maybe put some vinegar in the vial, drop some test solution and take note. you will see a bright pink color. add some of the base solution and you will see the color change in the vial....do this before you mess with your actual nutrient solution just to get a feel for the colors! 5 stars for: price, reliability, longevity of the product use and ease of use. General Hydro is kind of the "big boss" hydro company and they really know what they are doing. Every product thus far I have purchased is good.
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Reviewed in the United States on January 29, 2016 by Danni Boi
Size: Kit
It's a Ph kit. It does what it is advertised to do and does it well. The test kit works great and often is quicker and easier to use than my digital meter. The color chart is built right onto the label of the test liquid so you can hold up the test tube and determine which color it matches or most closely resembles.
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Reviewed in the United States on December 30, 2025 by Will
Size: Kit
Excellent product you don’t need much to change the pH up or down reasonably priced
Reviewed in the United States on March 7, 2026 by Dennis F.
Size: Kit
I've used this product for a long time, the stuff works awesome. Only issue is had was when it showed up the Testing liquid seemed to have leaked all over the inside of the bag making it nasty. It's happened before and will probably happen again, but the stuff works awesome so I'll keep ordering.
Reviewed in the United States on June 22, 2025 by Dud
Size: Kit
Got a lot for a great price
Reviewed in the United States on February 24, 2026 by Eric Woody
Size: Kit
My shipment arrived slighly 'wet' inside the plastic bag and the paper labelling within; however, each indivdiual jar was properly sealed -- so... dunno where the wetness came from.. The product itself works well; test is easy to conduct and easy to read with sufficient color variation to divine even 7 vs. 7.5 vs. 8 PH, etc. PH down is quite strong, a little goes a long way (about 1 capful pulled my 3 gal bucket down from 8.0 to 7.0 when measured again after 3 days). If I had a suggestion would be to also sell this kit in lower cost formats that do not include one of the PH up's or PH down (i.e. I dont really see myself using the PH UP, so therefore I would have preferred it not be included in the price).
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Reviewed in the United States on May 8, 2025 by A Guy named Mike in Texas
Size: Kit
If you are struggling with yellowing leaves, stunted growth, or "nutrient lockout," the problem isn't your fertilizer—it’s your pH. This kit is the definitive "reset button" for your garden's health. Here is the expert breakdown. The Engineering: Chemistry Over Circuitry The beauty of this kit is its simplicity. Digital meters require constant calibration with buffer solutions; if you forget, your readings are a lie. The General Hydroponics kit uses a liquid indicator that provides a physical chemical reaction. It doesn't need batteries, it doesn't need "storage solution," and it never lies. pH Up (Base) & pH Down (Acid): These are professional-strength concentrates. In my 10 years of testing, the GH "pH Down" (the yellow bottle) remains the most stable and potent phosphoric acid-based adjuster on the market. It doesn't "rebound" as much as organic alternatives, keeping your reservoir stable for days. The Indicator Fluid: The bromothymol blue/methyl red spectrum is crystal clear. Whether you’re aiming for the "Peachy Orange" of 5.5 (Hydro) or the "Lime Green" of 6.5 (Soil), the color match is intuitive and nearly foolproof. Performance: The Science of Nutrient Uptake Plants are picky eaters. If your water is too alkaline, they can't "see" the iron or manganese. If it's too acidic, they can't "see" the phosphorus. By using this kit to dial in your water to the 5.5–6.5 range, you are essentially opening the "buffet line" for your roots. In my side-by-side tests, plants adjusted with this kit showed 25% faster growth than those given "raw" city tap water. PROS Absolute Reliability: No sensors to dry out, no batteries to die, and no "calibration drift." It works every single time you use it. Extremely Concentrated: A single 8oz bottle of pH Down can treat hundreds of gallons of water. You only need a few drops to move the needle. Complete Starter Set: Includes the test vial, the dropper, and the indicator fluid. It’s a "lab-in-a-box" that requires zero extra purchases. Shelf Stability: Unlike digital probes that have a 12-to-18-month lifespan, these chemicals stay potent for years if kept in a cool, dark place. The "Double-Check" Tool: Even if you own a high-end digital meter, every pro-grower uses this kit as a "sanity check" to ensure their meter isn't lying to them. CONS Subjective Color Reading: If you work in a dimly lit grow room or have color-vision deficiencies, matching the liquid to the chart can be tricky. (See my Pro-Tip below!) The Staining Factor: The indicator liquid is an intense dye. If you spill it on your carpet or white countertops, it’s permanent. Handle with care. Manual Process: It’s a bit more time-consuming than a 5-second digital dip. You have to fill the vial, add the drops, and compare the color. Overall Input The General Hydroponics pH Control Kit is a masterclass in functional utility. It is the foundation of a successful harvest. While it may feel "old school," it provides a level of certainty that digital tools simply cannot match for under $100. It is rugged, reliable, and technically flawless in its execution. Reviewer Pro-Tip: To get the most accurate reading, always check your color under "Daylight" (5000K-6500K) lighting. High-pressure sodium (HPS) or blurple LED lights will distort the colors of the liquid, making you think your pH is higher or lower than it actually is. Also, adjust your pH AFTER you add your nutrients, as most fertilizers will naturally drop the pH of your water! Who is this for? Hydroponic enthusiasts, Coco Coir growers, houseplant parents using Reverse Osmosis (RO) water, and any gardener who wants to eliminate "mystery" plant problems once and for all.
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Reviewed in the United States on January 4, 2026 by Mr. Review
Size: Kit
Very easy to use. Highly recommend.
Reviewed in the United States on January 26, 2026 by H.Howell