How do I fix my pH lockout?
Elijah King
Updated on March 19, 2026
How do I fix my pH lockout?
How to Fix Nutrient Lockout
- Stop feeding your plants.
- Flush your plants with water.
- Make sure your growing system is fully saturated.
- After flushing, let your soil completely dry out before you water your plants again.
- Afterward, water your garden normally for a while before you reintroduce nutrients to your plants.
What causes lockout in cannabis?
Nutrient lockout is when cannabis plants cannot absorb nutrients properly. They are starving even if they are given plenty of food. Funnily enough, the nutrient lockout can make your plants seem like they are underfed. This is caused by one of the key parameters of successful growth being out of whack.
How do you flush for nutrient lockout?
Similar to nutrient burn, the best way to take care of nutrient lockout is to flush your plants. By clearing out your growing medium you rinse out the built-up salts that are causing the lockout. You can use plain, fresh water to flush your medium without any nutrients until the blockage clears.
Does Cal Mag raise or lower pH?
Fertilizer with high nitrate nitrogen, like 15-5-15 Cal-Mag, has the effect of adding 131 lb of calcium carbonate (limestone) for each ton of fertilizer used by the plant, or in other words, to increase the pH of the growing medium.
How do you fix soil pH?
What Can Be Done to Correct Poor Soil pH? Overly acidic soil is neutralized with the addition of limestone (available at garden centers). Powdered or pelleted agricultural limestone is most commonly used. Don’t overdo lime – it is much easier to raise pH than to lower it.
Can overwatering cause nutrient lockout?
Droopy branches and leaves, yellowing leaves, or drying out are common issues. These symptoms are signs of not only nutrient lockout, but under-watering, over-watering, wind burn, and general nutrient deficiencies.
Does perlite affect pH?
Perlite is crushed aluminum-silica volcanic rock, which has been heated rapidly to very high temperatures, during which process it expands to a lightweight, chemically inert, and sterile material. Perlite has no nutrients, and with a pH of 7 to 7.5 (neutral) it does not contribute to the substrate pH.
What does pH lockout look like?
Nutrient lockout will resemble a nutrient deficiency—plants will be weak and flimsy with stunted growth. Any yellowing or curling of the leaves also indicate that the plant is experiencing nutrient lockout. Cannabis plants may look like they don’t have enough nutrients when in fact they have been given too much.
How do you adjust pH?
If the pH is higher than desired, adjust it using a hydrochloric acid solution. If the pH is lower than desired, adjust it using sodium hydroxide solution. Fill a plastic pipette with the correct solution, add a few drops to the solution in the beaker and wait at least 20 seconds before reading the pH on the meter.
Can you add too much CalMag?
Just make sure you don’t overdo it when adding to the nutrient solution. Just 0.5ml per Litre is fine in most cases. CalMag contains 3.2% calcium, 1.2% magnesium , 0.1% iron and 2.6% nitrogen.
How does Cal Mag affect pH?
Fertilizer with high nitrate nitrogen, like 15-5-15 Cal-Mag, has the effect of adding 131 lb of calcium carbonate (limestone) for each ton of fertilizer used by the plant, or in other words, to increase the pH of the growing medium. The opposite occurs at pH higher than 6.5.
How to prevent nutrient lockout in cannabis plants?
No matter the cannabis plant issue, you must learn from the experience. As crucial as it is to identify and solve nutrient lockout, knowing how to prevent it is even more critical. Whenever you plan to change your nutrient plan, do it gradually. Check the pH of your growing medium regularly and flush whenever necessary.
How do I get rid of nutrient lockout?
Water with water that has the correct pH level and the problems from the lockout caused by improper pH should go away in a few days. Sometimes, the requirement to feed your plants heavily can be the main reason for a nutrient lockout.
How do I know if my plants have nutrient lockout?
Being interested in and worried about your plants is already half the battle of identifying a nutrient lockout. This health issue will make plants look and feel weak. Growth will appear to be stagnated. You’ll be seeing yellowing in the leaves. Left untreated, this yellow will turn brown and the leaves will curl up, looking burnt.
What is an example of a nutrient lockout?
Examples of these include iron, zinc, copper, manganese, magnesium, and cobalt. If your plant has a nutrient lockout, it can’t absorb these nutrients, which lie in wait in the root zone. While it can happen in every growing medium, the most susceptible are coco coir, soil, and rockwool.