It can be helpful to make a note of the total amount of pH up/down added. The total amount of used pH up/down will be about the same each time. The amount will change a little depending on which nutrients your plant is getting for its current stage of life, but having a ballpark figure is really helpful.
Watch our video above to see Nebula give a demonstration! Unfortunately there’s no exact formula to adjusting pH, because factors such as the source of water, growing medium, nutrients, drainage and growing setup all have an effect on pH. You will need to use trial and error to figure out what amount of pH Up or Down works for you in your setup with your nutrients. If you’re new to adjusting pH, start small with pH Up and Down, and only work your way up to bigger amounts after you’ve gained some experience. Most growers will be able to figure out their personal measurements within 1-2 waterings. The very first time you pH your water, it will take a little trial and error to figure out how much PH Up or PH Down to add to get to the right number, since everyone’s water is a little different. The general idea is to start with a little bit, maybe a few drops, then retest and add more if needed. Continue this until you get the water in the proper range.
PH Down is much stronger than PH Up, so be extra careful with PH Down! After the first time, it will be much easier to measure out how much you need. Tips for Cannabis Nutrient & pH Management: Don’t Go Overboard: With liquid nutrients, it’s usually better to give too little than too much. You can always add more, but it’s harder to take nutrients back. A good rule of thumb is to start out at half the recommended dose, and only raise nutrient levels if the plant needs it. Never Mix Nutrients or Supplements Directly With Each other: Always add nutrients directly to your water. They can react with each other in a way that can make nutrients less available to your plants. Most nutrient bottles or pH adjusters will come with a clear warning that says the same thing. Always add any additives directly to the water – your plants will thank you for it. Add “Micro” to Water First – If you’re using a 3-part nutrient series with a bottle for “Micro,” you should always add that to the water first. It will also say so on the bottle and on the nutrient schedule, but just something to be aware of. Tap Water Can Be Easier to pH Than RO or Highly Filtered Water: Tap water or mineral water has an extra buffer of extra minerals and other “stuff” in the water. This helps prevent the pH from swinging up too high or too low quickly and can make pHing easier. RO water has very little buffer (it’s basically pure water) and tends to swing up and down in pH easily with just a little pH Up or Down. Do you need special water or is your tap water good enough? Shaking Water Changes the pH: When checking and adjusting pH, some growers like to shake their water container to make sure everything is evenly mixed. This works well, and roots love the extra dissolved oxygen, but it’s important to understand that after shaking the nutrient water for a long time, the additional dissolved oxygen will raise the pH of the water. Don’t worry about this – don’t retest then readjust the pH. If you’re going to hand-water to your plant, you want to make sure you go by the pH of the water before it was shaken up. In hydro, the water is going to be oxygenated anyway, so shaking it before testing is ok. If water is allowed to sit for a while, it’s normal for the pH to change a bit. When it comes to mixing, make sure you mix water gently so nutrients and pH Up or Down are evenly distributed, but avoid vigorous shaking until after you’ve already adjusted the pH. Try to keep pH in the suggested range and you’ll be fine, even if it’s on the higher or lower end of the scale. 1.) First get a ballpark figure of the current root pH. Next time you water the growing medium, test the pH of the water going in.
Test the pH of the water that runs out of the bottom (runoff water) If the pH of the runoff is in the right range, even if it’s not the same as the pH you put in, you’re good. If the pH of the runoff water coming out is too high or too low for your range, you know that you’ll need to correct the pH.
Test the pH of the reservoir by taking a small sample of water and use it to test the pH. If the pH is outside the 5.5-6.5 pH range, you know you’ll need to correct the pH. Tips For hand-watered plants… (soil or soilless) Think about the pH of the water that you watered your plants with. So if the pH that comes out the bottom is outside the range, that means you need to either raise or lower the pH to get it back where it should be. Flushing – pH problems are sometimes caused by over-fertilizing (the plant was given too many nutrients or supplements, which builds up salts in the growing medium).