Expedited Shipping to all of Canada & USA. Express Shipping to over 154 Countries Worldwide!

ph test indicator 237ml

by General Hydroponics

Price: $24.99 + $33.47 Shipping
In stock
Fill a test-tube halfway with nutrient, add a few drops of pH Test Indicator, and observe the coloration of the liquid in the test vial. Use 3 drops per 5 mL of solution.
$24.99 + $33.47 Shipping
gaia green power bloom 2-8-4 10kg gaia green power bloom 2-8-4 10kg

$43.64 $49.99 (12.7% off)

gh flora bloom 1 litre gh flora bloom 1 litre


clonex rooting gel 100 ml clonex rooting gel 100 ml


mfgar isopropyl alcohol 99.9% 4 litres mfgar isopropyl alcohol 99.9% 4 litres


canna coco brick 40 litres canna coco brick 40 litres


gh flora gro 4 litres gh flora gro 4 litres


plant saucer 25 plant saucer 25


sensi cal-mag xtra 500ml sensi cal-mag xtra 500ml


hydrofarm twist tie 50 meter hydrofarm twist tie 50 meter


rapitest soil test kit, 40 tests rapitest soil test kit, 40 tests


hm ph80s ph meter hm ph80s ph meter


hstr ph test papers (east) hstr ph test papers (east)


dutch treat ph test papers dutch treat ph test papers


bluelab cal sol'n ph7.0 236ml bluelab cal sol'n ph7.0 236ml


bluelab cal sol'n ph 4.0 236ml bluelab cal sol'n ph 4.0 236ml


bluelab 2.77ec conductivity solution 500 ml bluelab 2.77ec conductivity solution 500 ml


general hydroponics ph 7.0 32 oz general hydroponics ph 7.0 32 oz


general hydroponics ph test kit, 1-ounce general hydroponics ph test kit, 1-ounce


bluelab ph probe kcl storage solution 120 ml bluelab ph probe kcl storage solution 120 ml


Product details
Product Dimension: 20.32 x 20.32 x 15.24 cm
Shipping Weight: 1.25 Kg
SKU: 1423

Manufacturer: General Hydroponics

Date first available: March 16 2016
Customer reviews: Be the first to review this item
Bestsellers Rank: #2 in Measuring Device
Customer reviews

No customer reviews

You must be logged in to post a review

robb w.


August 18, 2015

Verified Purchase

Came quickly enough, didn't realize I'd run outta this stuff until the day my back-up pH meter crapped out on me less than a week after my good one died lol, so yea.... Desperate times. And although I ordered my new meter w the same transaction as this litmus solution, it's not expected for another week @ least while I've had my big bottle of litmus liquid over a week.
Another thing, u may wanna get u a bottle of this as backup even if u have a good pH meter, they all crap out/require calibration/ batteries die & it always seems to happen at critical times. Having this little cheap plan b can save u a lot if hassle and heartache, the small bottle I'd got of it when I ordered a pH adjuster kit n my early days is what clued me in to my meters being outta wack, probably saved a lot of issues. It's always good to have a back up like this, not really prone to the problems/ limitations of more "advanced" data collection devices

Ronnie Black


October 17, 2022

Verified Purchase

Your growing ph doesnt have to come down to the decimal point. As long as you are in range, your plants will eat fine. And this ranging scale is the best I have ever used. Its also the most accurate that I've ever used and I been doing this a long time (Im almost 60) and have been using this stuff for years. Why? Its cheap, and it works like a champ..Dont over think your grow. You dont need those 1000 dollar meters, growing isnt rocket science. Buy this, fill vial half way (very important) use 2-3 drops. I do this twice. Once with two drops and once with 3 drops..Its like cutting in carpentry...Measure twice and cut once...Same applies here. I've tested this with my coral reef PH Meter that was about 1000 bucks, because it monitors Ph 24/7 and Ph is extremely important when growing corals and this stuff is spot on



March 14, 2019

Verified Purchase

pH Meters are cool. They make testing your solution super easy and are a real time saver. Only problem is they are quite expensive overall, and are prone to drifting readings as well as general failure, no matter how well you maintain and calibrate them. It's gotten to the point that the only real issues I have with pH and in turn my plants, is when a pH meter decides is isn't going to tell the truth anymore and I see the deficiencies because of it. Tired of playing games and wasting money on them, only to be forced to double check the meter's results with drops anyway... So I just use these drops and no more issues.



May 21, 2017

Verified Purchase

Works perfectly. Cost only a couple of bucks more than a 1-ounce dropper bottle of the stuff. Use a plastic pipette to measure out drops directly from this large bottle or refill a smaller dropper bottle*.

*Be warned that attempting to pour out of the completely FULL bottle into another container is tricky and can make a mess - this stuff will semi-permanently stain many types of surfaces, like a porcelain sink. A rag dampened with 50/50 bleach and laid over the stain will usually remove it, but that's not assured and could damage the stained surface (but not a problem with porcelain).



June 15, 2019

Verified Purchase

I use this to test the ph of my drinking water and also the ph of the water I use to grow hydroponics. I also have a digital ph meter (the button batteries just died), so that's why I'm getting this again. Just remember, the water from a faucet or bottled water always seems to be too acidic (Usually around 6.0ph-6.8ph), and the ph scale goes from 0-14, so 7 is neutral and 6.5ph is too acidic for my drinking water because our blood ph is around 7.35-7.45ph, so I always alkalize my water and this is an accurate product to measure with.... most likely I will buy again when I run out



January 12, 2015

Verified Purchase

This is simple to use and accurate. But the 6.5 color swatch on the bottle does not exactly match the actual color of the water in that range (a printing problem?). It looks more golden. It is not orange like the 5.0 swatch but it could be haphazardly misinterpreted as an orange 5.0 match. But when adding four drops of the test indicator to the vial, some of the color is dark green before the indicator is mixed with the water — and that's how I know it's in the 6.5 range. That's my experience, what's yours?



May 06, 2015

Verified Purchase

Just A giant version of the smaller bottles that come with the testing kit or ph up/down kit. It comes out to be 8 of those smaller, dropper style bottles. This larger 8oz version does not have any dropper on it.

It's basically a refill supply. Make sure to keep it in the dark cooler places for storage. Also, when filing your smaller bottle(s), buy a plastic eye dropper or pipette, and just squirt the solution in.. do NOT try to pour it... it will dribble and spill. You were fore warned heh.



March 27, 2022

Verified Purchase

I've use this brand for a loooong time now and hasn't ever disappointed me. It's accurate and easy to use. This is a refill bottle for the smaller one they sell that comes with the vial. I'd highly recommend it. My hydroponic vegetables grow great using this to keep my ph in check. The only downside I can see is if you're color blind this is not a good product for you. I hope this review helps someone out and if so hit helped I like to see if my review helps someone. Have a great day!!!!



January 28, 2016

Verified Purchase

This is the best way to check the PH of your hydroponics system, or your swimming pool or tap water or about anything really, and this bottle is HUGE compared to the other test kits. Refilled my smaller bottles with this, should be able to refill them 10 times I bet. If you check your PH a lot this is the way to go. keep my DWC hydro at 6.0. Tap water is usally 7 to 8. baking soda will raise PH, Vinager will lower PH. 1 to 2 drops of vinager per gallon drops it 1 point. about perfect.



August 20, 2021

Verified Purchase

I have tested it against a pen a couple times and find it close or right on all the time, what I mean by close is the color is hard to read from 6.0 to 6.5 the sweet spot I’m looking for, I like it because I don’t have to keep calibrating a pen great for a quick test to see where you at, there is a picture on the net with the different colors in the vial that really helps and I hold the vial against e white sheet of paper have already purchased it again definitely would recommend

1 2 3 4 5 6 7 ... [21] >