TDS (Total Dissolved Solids) - Cannabis Lingo

As a cannabis grower, there’s a range of terminology that you’re going to need to be familiar with and understand to be successful. In this article, we’re going to be discussing Total Dissolved Solids.

What are Total Dissolved Solids?

Water contains all kinds of organic and inorganic matter that's dissolved in small quantities. Total Dissolved Solids refers to the total minerals and salts that are dissolved within the water. Regardless of the water being for drinking or watering your plants, the Total Dissolved Solids are mainly made up of inorganic salts and can result in aesthetic or taste differences depending on the source.

The concentration of TDS are measured in Parts Per Million (ppm), 1ppm would be equivalent of 1mg/L.

Tap water generally has a TDS of 200-400ppm. Distilled water can have a TDS as low as 0ppm. While water this "pure" may sound appealing the various salts and minerals found typically in tap water is actually crucial for human, animal, and plant life. Water with high levels of TDS can reach readings of 700ppm or more.

The effects of too much, or too little TDS can result in a strange taste, the water looking coloured, hard water and scaling, and corrosion.

Why does TDS matter?

Unlike plants grown in soil, when you’re using a hydroponic grow system, the plant gets all of its nutrients from the water. Having too many nutrients in the water can be as damaging as not having enough.

Too many nutrients and your plants root system could shut down, causing the plant to stop absorbing nutrients altogether. Not enough nutrients and your plants won’t benefit from the added boost or grow to their full potential, leading to smaller yields.

Controlling your TDS levels

Knowing your TDS range will help you to control your plant growth. Using a TDS Pen or EC Meter, you’re able to measure the total dissolved solids in your reservoir. When you purchase a BCNL Grow Box, we provide you with nutrient schedules to take the guesswork out of growing quality plants.

Our schedules will help ensure your plants are getting the proper nutrients, in the proper doses, at the proper times to produce the highest yielding plants possible. There may be some instances where toxic substances are found and you’ll need to implement some kind of water filtration or reverse osmosis system. In these cases, you may need to speak with a water treatment specialist to find the best solution for your needs.


The TDS levels of your water will vary greatly depending on where you live, the water treatment systems currently in place and the overall source of the water (among other things). With the purchase of a TDS pen or a Tri Meter, you’re able to monitor the levels and alter them using nutrients to get the best yields possible.