Note: After adding nutrients (or even if you’re giving just plain water), always pH your water to 5.5-6.5 before giving it to your plants. This is important!
Best Nutrients for Coco
How much Cal-Mag should I use for coco coir?
Poor Nutrients for Coco
At the very least, make sure pH is the first thing you check if you start seeing nutrient problems!
The standard for soil and coco coir grows are fabric pots, because they help to aerate the root system, they are convenient to ship and they are easy to store. Here is an example of what you might want.
Vegetation (weeks 2-5)
Best Nutrients for Coco Coir – Ironhead Method
To get started with your seeds, see our article for tips on germinating cannabis seeds. A classic way to transplant seedlings after they’ve germinated is using plastic solo cups with holes cut in the bottoms to allow for drainage, though any small pot will work. Ironhead says he only “bottom feeds” the plants until they have 3-4 sets of leaves. By this he means place the cups/pots in a tote and fill the tote with nutrient solution. In my experience this isn’t completely necessary, but while watering you just need to be careful with young plants. You should start the plant with full strength vegetation nutrient solution.
When growing with coco coir, you want to aim for 10% runoff each watering. You also want to make sure the plant is never sitting in runoff. This is generally whats used to avoid your plant from sitting in its runoff.
A different grower added, “Canna – I have only used their coco line, but it is the highest quality you will find.”
This combo is a crowd favorite – many coco coir growers write in to tell us this is their favorite cannabis nutrient for growing in coco coir. Get a custom nutrient schedule from Canna or use this pre-made one [JPG].
Use “Grow” in the vegetative stage, and “Bloom” in the flowering stage. Organic. Claims to be usable in hydro, but I’ve only seen growers use it in soil so that’s what I’m recommending it for
What’s the Best NPK Ratio for Cannabis Nutrients?
Phosphorus tends to increase the number of flowers, while Potassium helps increase the bulk/weight of flowers. Be careful, though because going overboard with either one can burn your plants!
The House & Garden lineup is an expensive but effective line-up. From a grower: “H&G was started by a top researcher from Canna. They are right outside of Amsterdam and because cannabis is legal there, so both Canna and H&G are able to do R&D using cannabis. I don’t know about Canna, but I know that House and Garden makes all their own nutrients in-house and they work great.”
Examples of Good Can nabis Nutrients
Follow the instructions on the side of the bottle at half-strength for great results in soil or coco. It’s recommended to also use a Cal-Mag supplement if using filtered water, growing in coco, or using and LED grow light (all tend to increase the Cal-Mag needs of your plant). I prefer the GH version called CaliMagic, and use at 1 tsp/gallon.
Use the “hydro” version of Fox Farms nutrients when growing in coco coir. Two bottles are the same as the soil trio, but the “Grow Big” bottle is formulated slightly differently for a soilless grow. Follow the feeding schedule (here’s a PDF, here’s a JPG) from Fox Farms at half-strength to start. Generally, the Fox Farms nutrient system will prevent Cal-Mag deficiencies, but it’s good to have extra Cal-Mag on hand just in case whenever growing cannabis in coco coir, if using filtered water, or if growing with LED grow lights.