PH is massively important to your plants diet, and knowing what pH meter to buy for growing cannabis is crucial. You need to know for sure your pH meter is giving you accurate, reliable readings.
When you first start to look for what pH meter is best for growing cannabis, you will see many brands, and models. Though these will all work, some will be far more reliable and accurate than others.
Because pH is such an important factor to the diet of your plant, it is important to make sure you have the best ph meter you can afford.
Do not buy cheap!! There are places you can cut corners when growing cannabis if you’re on a budget. But when you’re looking for what ph meter to buy for growing cannabis, you don’t want to take the risk with buying cheap, unreliable equipment.
In this guide, we will go through a list of what pH meters you should buy for growing cannabis. These models are all tried and tested by cannabis growers for years, and are very reliable!
If you are having trouble deciding which pH meter to buy, feel free to ask for advice in our cannabis growers forum
- Why is pH Important when Growing Cannabis
- How to Test pH
- Best pH Meters to Buy for Growing Cannabis
- Testing pH of your Feed
- How to Adjust pH of your Feed
- Adjusting pH Organically
Why is pH Important when Growing Cannabis
Cannabis prefers soil, or a medium, that is slightly acidic. If the pH of the root zone, is not within the correct range, your plant will not be able to absorb the nutrients it needs to grow healthily.
If the pH of the medium is off balance, your plant will suffer with stunted growth, and nutrient deficiencies. It is crucial to ensure the medium is always within the right range, and the best way to do this is with a good reliable ph meter.
Different mediums will need a different level pH. Hydroponics and coco prefer a more acidic medium than plants grown in soil. It is important know which pH range you are aiming for, and how to keep it there.
pH in Hydro
Hydroponics is a method of growing plants, without soil. This can be growing plants in a nutrient solutions, rockool, coco, clay pellets etc.
When growing cannabis in hydroponic setups, it is important to make sure the pH of your feed, and the medium or reservoir, is always between, 5.8, and 6.2.
Letting the pH “swing” between these levels will allow your plant to access all of the nutrients in the medium.
A cannabis plant in veg, will prefer slightly more acidic mediums than a plant in flower. But only by a little. Keep vegetating plant around 5.8 pH, and keep flowering plants within 5.8 and 6.0
As long as you are providing your plant with the correct level of nutrients, it will be happy throughout its life cycle if you keep the pH at 5.8
pH in Coco
Coco, is seen as the middle ground between growing in soil, and growing hydro.
When you grow cannabis in coco, it will be treated as a hydroponic medium. This is becuase coco is void of nutrients, and has very good drainage and air to water ratio.
You will feed plants growing in coco everyday, and never feed them just water. You should use the same pH level for coco as you do for hydro. That is 5.8 for vegetating cannabis plants, and a little higher for flowering plants at 6.0.
Letting the pH swing between 5.8 and 6.2 is ideal, as this gives a good range for your plants to pick up all of the nutrients they need.
pH in Soils
Growing cannabis plants in soil, is a little different. In most cases, if you’re using a good soil, that has been buffered with dolomite lime, so the pH will rarely need adjusting.
Even though pH is easy to mange in soils, you should still try to make sure the pH level are optimal for the medium. You can do this by feeding the plant with water or feed at the correct pH level.
Cannabis plants growing in soil will prefer a slightly less acidic medium, than plants growing in hydro. Keeping the medium around 6.5 to 7.5 will be fine. This will give your plants all the nutrients they need, as it is readily available to them.
In some cases, a grower might be using soil to grow organically. If this is the case, then you will use the same pH level as you would growing in soil with salt based nutrients.
The difference with growing organically, is the way you have to adjust the pH if you need to. Rather than using chemical pH up and down, you will need to use other methods, like baking soda, or lemon juice, to alter the pH. But we will get into that later.
How to Test pH When Growing Cannabis
When you’re thinking about what pH meter to buy for growing cannabis, you must not look out for the cheapest model! These will give you an inaccurate reading, and will not be as reliable as you need them to be.
PH is massively important to your plant, and having good equipment you can rely on will give you piece of mind, and you will know for sure your readings can be trusted.
There are a few different ways to test pH, some are more reliable than others, but of course, as the reliability goes up, so does the price.
You can start of at the low end of the spectrum, with a liquid ph testing kit, but for best results, you need to go with a high end, reliable pH pen.
If you are growing on a budget, and buying a pH pen is out of your price range, you can get by, by using a liquid ph Testing Kit.
These are reasonably cheap, and some what accurate, but they are not the best solution for reading PH.
Liquid pH testers will involve you checking the colour of the solution, after you have added a few drops of the ph testing liquid. This is a problem though, as the water you’re testing, will often, not be clear. So judging the correct colour of your test, can be difficult.
Only buy a liquid pH tester if you are on a very tight budget. These will do the job to some extent, but for a more reliable reading, you need a proper pH pen.
You may have seen these devices in some gardens. A soil pH tester consists of 2 prongs, that get buried into the ground, with a reader on the top.
The reader will give you a rough estimate of the pH level of the medium, the moisture level, and sometimes the amount of light penetrating the medium too.
These are ideal for outdoor growing, and they are somewhat reliable. If you are growing outdoors, these might be the ideal tool for you. But again, the best and most accurate way to measure the pH is by using a pH pen, or meter.
Best pH Meter to Buy for Growing Cannabis
The best way, to get accurate reliable ph readings, is to purchase a good, pH meter from a good manufacturer!
PH is so important to your plants health, that you can not cut corners here. It is a waste of money to buy a meter that will not work after a few tests, or whill not provide you with accurate readings. You need your pH meter to be reliable! For the sake of your plants health.
There are many different manufacturers of pH meters. This can make it difficult to decide what ph meter to buy for growing cannabis.
These pens and meters may be a little more expensive than other brands, or methods for checking pH, but you can guarantee, they will provide you with trustworthy reliable readings for many grows! You just have to take good care of them.
Best pH Meters to Buy for Growing Cannabis
Taking into account all of the different ways to test pH, and all of the different meters you can buy, it isn’t easy to decide what pH meter to buy for growing cannabis.
Below are a few recommended names, that you can be sure you can rely on! These brands are tried and tested by growers, and you will not be disappointed with them. They may cost a little more than the cheaper models of pH pen, but they are for more reliable, and they will last a lot longer.
You may have already seen the essentials pH meter on your search for what to buy. This is a very popular brand of pH pen amongst cannabis growers.
They are reasonably cheap, and very reliable! This pH pen will give you readings to 1 decimal place, so you can easily tell if the ph level of what you are measuring is within the correct range.
The Essentials pH pen is also a tough piece of kit. Drop proof, shatter proof, and waterproof!
Getting this pH pen will give you accurate readings for at least a year, and if it is properly taken care of, it can give you reliable accurate readings for up to three years!
Hanna, are a high end company that make quality equipment. The price of their models can be high compared to other pH pens you might be thinking of buying. But their quality, makes up for the extra cost.
This particular model of ph pen from Hanna, will measure the temperature of your feed, to give a more accurate reading of the pH. Also, you can extend the life of this model by buying replacement prongs!
This means you can save much more money in the long run, by buying replacement rods when the older prongs get salt built on them from hundreds of tests.
Keep your pH pen clean, and it will last longer. But even when the prongs run out of life on this one, you can replace them! This makes it a great investment for a long term grower.
Blue lab pH pens are the go to pH pen for cannabis growers. They have been top of the game for many years now, and are well trusted amongst cannabis growers.
These pH pens are also a decent price, a little more than essentials, but a little less than Hanna.
It will adjust your reading according to the temperature of the feed, and will also give you accurate precise readings for years after purchase.
Bluelab make a whole range of pH meters too, this isn’t the only one. This is the best model to get for Percys Growers, as it is not very expensive, but it is very reliable. This is a pH meter you can trust!
Testing pH of your Feed
No you have some information on what pH meter to buy for growing cannabis, and what levels your pH should be, it is a good idea to make sure you are aware of the correct ways to use it to test your feed.
Everytime you feed or water your plants, the pH of the feed, will have an affect on the pH of the medium. To keep a balanced medium, you should always pH your water/ feed to the correct level before pouring them into the medium, or feeding the to your plant.
The pH check is the last thing you do before feeding. After you have mixed up your nutrient solution, and your plant is ready to be fed or wartered, let the mix sit for ten minutes. This will help all of the nutrients in the solution disperse properly.
More accurate readings can be taken once everything has dispersed through the water properly. So after letting the water/ feed to sit for ten minutes, check your pH, and adjust accordingly.
When the pH is set to the correct level for the medium you are growing in, then it is safe to feed your plants.
Testing the pH of your Medium
Testing the pH of your medium is not as easy as checking the pH of your nutrient solution.
There are a few good ways to do this. First off, you can use a soil pH tester, to give you a rough reading of what the pH of the medium is.
Alternatively, you can water your plant with the right nutrient solution at the correct ph. Then, when the runoff comes out of the bottom of the pot, collect it, and measure the pH.
The runoff will give a rough idea of the ph of the medium. If you have been watering and feeding correctly, the pH should come out of the medium, either the same as it went in, or a couple of points either side of the optimal level.
Testing pH in Hydroponics
For hydroponic setups, checking the pH is much easier, especially if growing using full hydro, like DWC or NFT.
You can check the pH of your reservoir the same way as you check the EC of your feed.
Use your chosen method of pH testing, ( liquid, soil tester or pH meter) and check the pH of the reservoir. Adjust accordingly and try to keep the level at 5.8.
The pH might fluctuate if the feeding balance is off. So monitor the EC of the reservoir as well as the pH. Monitoring these two readings will give you a good idea of how much your plant is eating, and whether you’re over feeding them, or under feeding them.
How to Adjust pH of your Feed
If at anytime the pH of your feed is off, there is a number of ways you can adjust it.
When you are growing using salts based nuits, you can use pH up or down, to alter the pH of the feed, before feeding your plant.
It only takes a few drops, as pH up and down, are very concentrated! It is also best practise to not use both pH up, and pH down, in the same solution.
Use pH down to bring the solution to the right levels, and if you miss the mark, add water to bring it back up again.
PH up is designed to take pH from (let’s say) neutral at 7.0, and make it go up, to 7.5, 8.0 and so on.
This is rarely used by growers, as it will make the pH of the feed, or medium, rise, and become more alkaline.
PH up is only used to correct mistakes when pH has gone too far past the optimal levels. But try not to use pH up and down in the same solution.
PH Down is used by a vast majority of growers. Most water used from the tap, will come out around 7.0-8.0, and this is too alkaline for cannabis to grow in comfortably.
To make the pH of the medium or feed fall, to a more acidic level, you will use pH Down.
PH down is very strong, and even just one drop, might be enough to change a litre of water into the right level, sometimes one drop might even be too much.
It is good practise to take 25 ml of pH down, and add it to 1L of water. You can then use the water solution, to adjust the pH of your feed. Doing this will make it much easier to get the correct pH, as the fall will be more gradual.
Stir the solution well, and the check the pH. After finding the correct levels, it is good to let the solution stand for five minutes before doing one more final check.
This will ensure the pH of your feed is on point, and ready to be given to your plant.
Adjusting pH Organically
If you are growing cannabis organically, then you may not want to use pH up and down for your plants. Instead, you can find organic alternatives.
There are some companies that do have organic pH up and down. You can use these, but they are essentially a bottle up version of cheaper ingredients.
How to Lower pH Organically
To make your medium a little more acidic, and bring it to a level where it is more suitable for your plant, then you can add these things to your water before feeding:
Lemon or Citrus juice
Adjust little by little, be careful not to go over. If you do, add some more water to the mix, rather than using pH up and down in the same solution.
How to Raise pH Organically
To raise the pH of your feed organically, you can simply use some organic baking soda. Use a little at a time to make sure you don’t go too far over the ideal pH ( 6.5-7.5)
PH Buffers in Soil
When you use soil to grow cannabis, it is usually treated with something to help buffer the pH. Usually, “Dolomite lime” is mixed with the soil before use, this will help keep the pH at the correct levels.
You have to be careful if you are using dolomite lime to adjust the pH of your medium, as it can be very strong, and have a lot of nutrients in it. Too much, and you risk giving your plants nuit burn.
On a final note, when growing cannabis organically, you should never use chemical based pH up or Down! Doing so will be detrimental to the growth of bacteria in the medium, and in the root zone.
Bacteria is very important when growing cannabis organically, and you do not want to have any detrimental impacts on their survival. Only use organic products when you grow organically. Mixing things up will not be good for your plant.
Final thoughts on What pH Meter to Buy for Growing Cannabis
There is no price you can put on peace of mind. Spending just a little more, can take you from estimated pH readings, to spot on to 1 decimal place pH readings.
Do not buy cheap models! If the models above are not within your budget, then you’re better off using a liquid pH testing kit, rather than a cheap pen.
For your first grow, you can use the liquid pH tester if the models suggested here are out of reach. When you are using your own home grown, you will be able to save some money for upgrades for your next grow.
Make sure pH meter is on that upgrade list, and buy the best one you can afford, your plants will thank you for it.
Thanks for reading our guide on what pH meter to buy for growing cannabis, I hope it gives you some answers and you know what to go for now.
If you have any questions or additions you would like to add to this post, then please comment below, or join the discussion in the forum.
Stay safe out there! And happy growing