Nutrients, pH Up and pH Down








The Essential Nutrients


Like humans, marijuana needs nutrients to survive and grow effectively. They harness nutrients to aid in development of their root structures, stimulate vegetative growth, and provide a critical foundation for substantial bud yields. There are over 20 nutrients that marijuana needs for proper growth, but the main nutrients a marijuana plant uses are Nitrogen (N), Phosphorous (P), and Potassium (K).

If you are interested in understanding more about plant nutrition, Wikipedia has a great page that discusses nutrients and their role in plant life. It is worth examining at least once for fundamental understanding even though much of it is not necessarily practical knowledge.




The Labels on Nutrients Tell you The N-P-K Concentrations

What Nutrients to Use and When


The process of feeding your marijuana plants is relatively simple. All it takes is adding nutrients into the fresh water reservoir of your hydroponics system thus turning it into a nutrient solution. The more pertinent questions to ask though are what nutrients you should use and how often you should use them.

When I first got my hydroponics setup from Stealth Hydro, they provided me with 3 separate types of nutrients.
  • Micro – Used at all stages of marijuana growth. It provides the multitude of nutrients needed in smaller quantities such as Calcium, Iron, & Silicon.
  • Grow – Used in the vegetative stage. It is heavy in N with moderate amounts of P and K.
  • Bloom – Used during the flowering stage. Heavy in P and K; no traces of N because it is detrimental during the flowering stage.


Leftover Powder Packets I Never Used. GH Flora Series is Superior in Every Way.

These nutrient packets they provided all came in a powder form. To add the nutrients, all I had to do was add a little to a glass of fresh water, mix it in and let it dissolve, then dump it in the water reservoir.

There were 3 major problems I didn’t like about these particular nutrients though.
  • It came in powder form, so it was annoying trying to manage that and keep undissolved particles out of the reservoir, so it wouldn’t interfere with functionality of the water pump.
  • There was no instruction or guidance. I just had to guess and check the amount of nutrients to use and most of the time I was wrong and my plants suffered for it.
  • The pH was very erratic and hard to manage with these nutrients. It was relatively easy to go way outside of the bounds of optimal pH ranges.
I wanted to eliminate a lot of these problems, so I looked into finding a suitable replacement. After a few hours of research, I found what I was looking for. The nutrient solution I have used since that time is called the Flora Series by General Hydroponics. It is much easier to follow because it has a feeding schedule, comes in liquid form rather than as a solid, and helps to control pH as well.





When I make big changes to my growing techniques, for instance changing nutrient brands, I always make sure to measure its effectiveness. After all, why change something if it isn’t going to do anything or give you even worse results?

That being said, my very first grow using the GH increased overall yield by 35% from 3.2 oz to 4.3 oz, and I have continued to get excellent results using these products. I would definitely recommend this nutrient lineup to anyone who wants an easy and effective nutrient solution.





Another brand of nutrients I see referenced a lot in growing forums is Advanced Nutrients. I personally have never used this particular brand, but a lot of people claim success with their lineups. The main reason I stayed away from AN is because I saw a lot of reviews that said they were overhyped and overpriced. I can’t weigh in on the overhyped part, but they are definitely priced higher than GH.

You can compare and decide for yourself; there are plenty of options for feeding your plants. Find the nutrients you think works best.




Standard pH Scale. Nutrient Solutions Need to Be Slightly Acidic at 5.5 - 6.5

pH and Absorption


If you are completely unfamiliar with what pH is, here is a basic explanation of what it is and why it is important. The pH scale is a measurement system to determine how acidic or alkaline a solution is.
  • If pH = 7, it is considered pH neutral. Pure water is neutral at 7.0 pH.
  • If pH < 7, the solution is considered to be acidic.
  • If pH > 7, the solution is considered to be alkaline.
pH is important because the pH levels of a solution must be in a proper range for your marijuana plants to absorb the essential nutrients. This proper range is slightly controversial, but I maintain a pH range of 5.5-6.5 as suggested by GH on their feeding schedule. It has worked well for me thus far.

Staying inside this range is critical because when the solution is outside of these ranges, the nutrients can no longer be absorbed into the water. Consequently, the plants will no longer have access to nourishment. This scenario is referred to as nutrient lockout. Avoid this at all costs by keeping a watchful eye on the pH levels of the nutrient solution.




The Milwaukee PH600 is Perfect for Measuring pH in Your Nutrient Tank

Measuring pH


Since pH is so important, it doesn’t take a rocket scientist to conclude that you will need a way to measure it. Accurate measurements in pH are critical because if the readings are incorrect, the subsequent actions you take to balance it will also be incorrect.





Early in my growing journey, I used paper testing strips that only need to be dipped in the solution a few seconds and compared to a color chart to determine the pH. After I had some experience though, I started to wonder if these strips were really accurate because my end results weren’t all that great, and I was getting heavy amounts of root rot which can be a sign that the nutrient solution is way too acidic.

Needless to say, I purchased a Milwaukee pH600, so I could feel more confident in my measurements. The reason I use the Milwaukee pH600 is because of its accuracy, low price, and other user recommendations.

When I received the tester, I immediately calibrated it and did a side-by-side test against the paper strips. I put the paper test strip in the solution and it read about 6.0-6.5 (these strips aren’t exact, so you have to kind of guess based on its color). I then put the Milwaukee in there and it showed the solution was at a pH of3.8! I was dumbfounded because the strips said I was doing fine, but my new pH meter was telling me there was a big problem. It was no wonder my plants weren’t producing anything and looked sickly and weak.



Balancing pH


So what do you do if your pH starts to creep outside of the optimal range? There are plenty of solutions to help you control your pH and raise or lower it as the need arises. I use the pH buffers provided by General Hydroponics, but again there are plenty of options for controlling pH out there. The choice is totally in your control.





I do recommend staying away from ‘home remedies’ though. For example, one common suggestion is to use Baking Soda to raise pH levels. The problem with this method is that you introduce a lot of dissolved solids into the system which makes it harder for the nutrients to be properly dissolved and absorbed. On top of that, you may be introducing other elements that may be detrimental or harmful to overall bud yields. Use something professional and specifically targeted for raising and lowering pH in a hydroponics environment.

Always remember that balancing the pH is one of the most important activities of a successful hydroponics grow. Daily measurement and balancing is absolutely crucial for bountiful harvests.




Give Your Plants Proper Nutrients to Get the Highest Yields

Action Steps

  • Research and decide on a brand of nutrients you want to use. Get them today!
  • Buy a device that will accurately measure the pH of your nutrient solution.
  • Decide on what you will use to control the pH of your hydroponics system.