Now Reading
Does Dolomite Lime Have Too Much Magnesium?

Does Dolomite Lime Have Too Much Magnesium?

Does Dolomite Lime Have Too Much Magnesium

Gold Header Ad

reserve your ad here

Howdy all. I’m The Rev, the author of True Living Organics, and I have 50 years of cannabis growing experience under my belt. Recently I have gotten several emails basically asking me the question: Does dolomite lime have too much magnesium? Well, my simple answer is no. And this is based on me using dolomite lime in my soil mix and in my water for almost a decade. Lemme ‘splain…

Using Dolomite Lime (and other things) in Your Soil Mix

To Learn Much More About All-Natural Growing Get My Latest Book on Amazon
To Learn Much More About All-Natural Growing Get My Latest Book on Amazon

Dolomite lime is about 22% calcium, and 13% magnesium (Mg). Now Epsom Salts are also high in magnesium. Epsom Salts are 10% magnesium (and 13% sulfur). So, you can easily see how using these two things in concert could subject you to some magnesium toxicity. Other soil amendments have pretty fair amounts of magnesium in them. Like, bone meal, crab meal, and greensand. On top of all these Mg rich amendments—some water sources (groundwater tap/well) can be a little, or even a lot heavy on Mg. Things like greensand, crab shells, and bone meal possess magnesium, but this Mg is available much more slowly than when dissolved into your water.

If you ID an Mg, or any other salt toxicity type of an overdose, just look at your soil mix, your water, and your amendments. See what you are heavy on that is suspect. Phosphorus and potassium are pretty high in probability here (usual suspects). Nitrogen could also be it. Magnesium, calcium, and sulfur always need to be generally monitored coming in as well.

Dolomite lime ‘could’ cause you to have an Mg overdose certainly. Or, a calcium (Ca) overdose. I mean it all comes down to how much Mg or Ca is coming into your dynamic before the dolomite lime, and from where. It’s pretty simple to fix your soil mix if you ID a problem. Cut it in half with bagged soil, like Ocean Forest and don’t make the same mistakes … boom!

Using Dolomite Lime in Your Water

Since obviously the quickest and easiest way to address any overdose when growing all naturally like TLO style, is to adjust your additions to your plant water. Many of you including myself use dolomite lime in the plant water to add calcium and magnesium—cannabis uses a lot of magnesium by the way—and to buffer the water’s pH. This is the easiest ever! Read on…

All you need to do is drop the PPM value of your plant water. I go in jumps of 5 or 10 PPM downwards. I normally would drop it 5 PPM and wait a week and see what I see, if they seem happier, I will drop the PPM by 5 more points. If they don’t seem happy after a week, I go straight back to using just groundwater (dechlorinated) on them. If this doesn’t fix things I then move on to potential soil additions causing my overdose expressions. Road rules:

  • Always strive to be at least generally aware of what elements are coming in to your garden and at what amount. Like I said before using Epsom salts and dolomite lime in your water is a combo that brings a LOT of fast Mg to the table. Your groundwater can have things like Mg, or Fe, and sulfur a little or a lot out of whack. Find out about yours.
  • If you use carbon filtering for chlorine, and your filter cartridges start failing, it will look a lot like an overdose of something, mimicking toxic salts looks. If your TDS meters are too far off from accurate, this will also usually cause an overdose look, with toxic salt levels actually being the reason. AKA, water PPM is actually too high.
Classic Salt Toxicity Signs on Leaves
Classic Salt Toxicity Signs on Leaves

Starting Out with Reverse Osmosis (R/O) Water

To start here let me say that this includes starting with rain and distilled water types. When using R/O type water and bumping it up 50-ish PPM with dolomite lime, I could see this being potentially problematic if the soil mix is also fat with magnesium. Here’s how I would do…

Calcite Cartridge for Buffering pH and Adding Calcium (PPMs) to Your Plant Water
Calcite Cartridge for Buffering pH and Adding Calcium (PPMs) to Your Plant Water

Go to Pure Water Products online and get yourself a calcite unit (filter cartridge and housing). This product exposes the low PPM water to calcium carbonate. This has two main effects. Calcium is added to the water giving it a PPM around 50, and the pH of the water hovers right around 7.0 pH—pretty much perfect water to start with is what it sounds like to me.

I want to say here I personally have no experience with calcite cartridges; however, I have heard from several peeps that rave about them. If I was starting out with R/O water now I would definitely use a calcite cartridge filter. It’s much simpler and I would still get a good amount of Mg from the dolomite lime and other things in my soil mix. Like I said before, cannabis uses a lot of magnesium (and calcium).

This is Normal Flowering Signs of Nitrogen Waning and Not Salt Toxicity
This is Normal Flowering Signs of Nitrogen Waning and Not Salt Toxicity

Using Dolomite Lime Alternatives

Diagnosing secondary (or micronutrient) nutrient overdoses is tricky, even for someone with my experience. They are similar in many ways with very subtle differences. Salt Toxicity looking signs can easily (normally) be handled by dropping the PPM of your plant water by 5 or 10 PPM. Identifying which nutrient is responsible is also fairly simple just by looking at your dynamic and what nutrients are coming in in what levels and from where. Knowing the makeup of your source water is also very important.

See Also
cannabis world news moon phases with skunk smoking a joint in front of budding pot plant

For your soil mix I told you above the ease with which this can be handled. If you are concerned with Mg in particular, switch to using ground oyster shell as half of your normal dolomite lime input. So, if you normally add 1 cup of dolomite lime to your 3-ish cubic feet of amended soil, just go ½ cup dolomite lime and ½ cup ground oyster shell. You’ll still get the buffering from the calcium this way without all the magnesium.

Start Out Your Sprouting Seeds Safely Always Using Bottled Spring Water
Start Out Your Sprouting Seeds Safely Always Using Bottled Spring Water

For your water just do like I said above using the calcite filter if using R/O water to start. If you want to stop using dolomite lime in your dechlorinated groundwater (The Churn), you can also add small amounts of ground oyster shell or agricultural grade DT (diatomaceous earth). These will give you a calcium bump and add a little bit to your PPMs.

Afterword

Alrightythen! I hope you will find this article useful. Want to read some more Rev now? Check this article out: Organic Growing Styles by The Rev. Make sure to check out my latest video on my YouTube channel about cannabis seed germination here: Rev’s YouTube TLO Video Regarding Seed Germination. And, last but by no means least, go by Kingdom Organic Seeds online and check out the latest release of Boggle Dragon, and so much more! L8r G8rs…

  • REv 😊

 

Share Skunk Magazine With Your Friends

© 2022 Skunk Magazine. ALL RIGHTS RESERVED.