A good way to use litmus.

[BigPete]

OK I hear a lot of ppl saying oh no, a ph meter is essential bit of kit, well I say I'm fed up with ph meters that dont hold their calibration any longer, some of them not cheap. PH paper is a far better way to tell your ph and how to compare small rises and falls while you adjust ph. Get a book of yellow ph strips and tear one off. Get a clean white plate. Cut the strips into shorter pieces about 6 or 7 pieces and place them on the plate. Now with a clean thin straw use as a pippete and place 2 or 3 drops of reservoir water on the first piece of litmas paper so that the small cut off is submerged in a bubble of water, dont touch it and leave for 10 15 seconds in its bubble of water. You will get a truer color reading this way. Adjust your reservor and repeat. You wil see a line of cut strips all a very slightly different color from each other indicating the water becoming either more acidic or alkaline. After a while you will get to read the colors better. This is the way I now test. Its cheap and fairly reliable. I probably get a bit of drift this way But thats not a bad thing

 

[BigPete]

There are many different electronic pH test meters on the market. However, good electronic pH test meters are expensive and often wind up giving you false readings, even if they are calibrated often and stored properly. General Hydroponics make very good pH drops.

PH test drops wont give you false readings, they don’t need to be calibrated, you don't need to buy calibration fluid for pH drops, don't need special care to store properly, and only cost around $5 depending on where you get them. Even of you buy an electronic pH test meter, make sure to have some pH test drops on hand so you can verify the readings your electronic test meter is giving you are accurate.


I've found a better way of testing ph using ph fluid and shot glasses. Use a shot glass with a measured amount of liquid from your reservoir. Use a syringe they're very accurate. Place 10ml of reservoir test fluid in the glass and place in front of a light source and add three drops of ph fluid. Add ph up or ph down to reservoir and repeat. From this line of shot glasses it is easy to see where your ph is at. At 20drops per millilitre a 10ml bottle has 200 drops, divided by 3 will give you 66 tests for around $5

 

[Palindrome]

I have to disagree, but each to their own right.

But a pH pen is the fastest and easiest way, for a simple pH messurement.
I have run aquariums for even longer then my growing, and have tryed a bunch of different liquid pH testers.

Non of them have been remotely as fast, easy or even as accurate as a cheap pH pen.

Personal I no longer care to buy brand pH meters, the cheap ones work fine and can be found on Ebay for as little as 5$ or amazon also have some very cheap ones that will work fine.

I have had Hanna instruments, milwaukee, BlueLab, Adwa and maybe a few other brands.
They all break and replacments cost a bunch, and for growing weed it don't matter if you have 0.01% accuracy or not.

You basicly just need a ball park figure, hence you can use the liquid tests just fine.