When you’re growing cannabis in any medium you have to make sure that the PH of your water is balanced.
Cannabis doesn’t like water that is acidic as it eats through the roots and causes the potential for various nutrient lockouts.
It becomes a dance between grower and plant as you look to keep your plant within a range it likes.
The potential of Hydrogen (PH) is a measurement that tells you how acidic or alkaline the water you’re giving your plants is.
Cannabis likes to stay between the ranges of 5.8 to 6.4 with some strains gravitating to various spots within the range.
As a grower, you’ll be adjusting the PH of your plants throughout their life cycle using a variety of products.
Various acidic products are used to lower the PH of your water but no source of PH is equal. Phosphoric and citric acid are commonly used, but growers looking to save some money often choose other alternatives like vinegar.
Vinegar is an organic acid that can be used to lower the PH of the water. It is important to note that your PH will be unstable as the water evaporates and the PH rises. Only use vinegar in an emergency situation or you’ll cause damage to your cannabis plants.
If you’ve started using vinegar as a PH down for your cannabis plants and have noticed any issues with your plant, it could be time to get something like phosphoric acid to replace it.
Vinegar can do more harm than good
Vinegar is also known as acetic acid and it has no beneficial minerals for your cannabis plant.
The interesting thing is when you add vinegar as a PH down it’ll lower it temporarily, but end up rising up as the water evaporates. Some growers argue that this is common with any water left out, but others say that the increase is higher when treated with vinegar.
This means that when you water your cannabis plants, in soil particularly, as the water evaporates it’ll make the water more alkaline again which could cause problems for nutrient absorption in your plant.
Using vinegar in emergency situations is ideal, otherwise use something like phosphoric acid which can actually benefit your plant.
Calcium and vinegar don’t get along either, calcium being a vital nutrient for your cannabis plants.
When adding it to your water you are breaking down some of the calcium that can be found. If you start seeing calcium deficiencies and are using vinegar as PH down then maybe add cal-mag or change products.
How much vinegar should I use?
Using a substance as strong as vinegar should be used sparingly. As with most things involving cannabis you’ll want to start low and test often.
Generally starting with a ¼ teaspoon will lower your PH by a full point.
Other products to use instead of vinegar
Most growers stick with food-grade phosphoric acid for their PH down needs as it isn’t organic (so it can’t go moldy) and is a stable acid which means that PH fluctuations are kept to a minimum.
Cannabis needs a large amount of phosphorus during the flower cycle and phosphoric acid can supply it.
Food-grade citric acid can be used as an alternative as well but it can be unstable and cause similar issues with PH that the vinegar has.
