The best hydroponic nutrients for your weed

Growing cannabis hydroponically requires devotion, fortunately there are loads of special nutrients on the market to make the job easier

Hydroponic cannabis cultivation can be tricky without the right nutrients.


Growing cannabis is an art form for some and as simple as tossing a few seeds in the ground for others. When it comes to hydroponics, however, it’s a little more complicated.

There’s no soil; it’s mostly water (with sand, gravel or coconut fibre used as a growing medium). And there are a few more variables to think about if you want to ensure good results. Those include things like pH balance and which nutrients to use to make sure your plants bust out some choice flowers and buds.

Keeping your plants healthy requires some devotion, whether you’re growing in water or soil. They’ll need attention at each stage of the growing process. Fortunately, when it comes to hydroponics there are loads of special nutrients on the market to make the job easier. 


Advanced Nutrients: Bloom, Micro, and Grow


  • Built-in “perfect pH” technology
  • Easy to use
  • “State of the art” formulation to allow maximum absorption in your plants


  • A little pricey, compared with other nutrients on the market

Fox Farm: Big Bloom, Grow Big, and Tiger Bloom


  • Phosphate-rich
  • Contains bat guano and earthworm castings
  • Bang for your buck: you can get 56 percent off the price right now with Groupon


  • Mixed reviews from some users online

General Hydroponics FloraGro


  • An industry mainstay—it’s the most widely used product on the market
  • “The choice of NASA scientists,” according to the company’s promotional materials
  • Currently being offered at cut-rate prices


  • The company was purchased by Scotts Miracle-Gro in 2015, messing with its brand roots as the choice among indoor cannabis growers

General Hydroponics GH Gardening Flora


  • Builds strong roots
  • Price point
  • Good for vegetables too!


  • Online reviewers say instructions for use are not the clearest; recommended strength can vary

Frequently asked questions

How often should you change your water when growing hydroponically?

A rule of green thumb (we are talking cannabis culture, after all) is to swap out your H2O every two to three weeks. But once a week is better. Some manufacturers suggest irrigating after three nutrient applications.

Is there such a thing as too many nutrients?

Hell yes. Fortunately, you can flush your plants before harvest to cleanse them of any excess nutrients. It’s recommended you do this two to three weeks before harvest.

What’s the best water to use for hydroponic growing?

Sounds like a trick question, but there is definitely an advantage to using distilled water (which is free of metals and other contaminants) over regular tap water, especially if you live in a city where the tap water isn’t that good.

How often should I water my hydroponics?

Water levels used in hydroponic systems will diminish as plants use up nutrients. The rate depends on indoor conditions and how fast your plants are growing. It’s a good idea to add water as needed—for example, during flowering, or when you notice your plants going through a growth spurt.

What should I do with hydroponic wastewater?

Reuse it on your tomatoes. There will still be nutrients remaining in the water, especially if you are changing it every other week.


As a way to grow cannabis, hydroponic systems are more particular. The good news is there’s more control. And if done right, better yields. There’s no soil to suck all the nutrients.

This post contains affiliate links. For more information see our disclosures here.

Leave your opinion for the editor...We read everything!

Your email address will not be published. Required fields are marked *