Nutrients & Grow Mediums

Macro and Micro Nutrients

There are three macro-nutrients Nitrogen (N), Phosphorus (P), and Potassium (K) these are the key players in just about all plants so almost all fertilizers state the NPK values as a percentage in the format "10-5-10" this would be 10% Nitrogen, 5% phosphorus, and 10% potassium.

Liquid fertilizers

To get you started here are two top picks for use in potting mix, coco coir, and deep water culture. Be warned nearly all liquid fertilizers, especially those with organic material in them, like fox farm big bloom or fish fertilizer are formulated to be very acidic (low PH) to keep them from going rancid over time. You will have to PH test your feed water and likely bring the PH back up to between 6 and 7 for soil or 5.5 to 6.5 for water culture. See the Meters and Testing section of the equipment page for everything you need. To measure out the nutrients Glass droppers are Ideal. These are the ones I use:

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Dyna-Gro

Liquid Grow & Liquid bloom are probably the simplest, most perfect, fertilizers. You just feed 1/4 to 1/2tsp per gal every time. PPM should be between 400 and 800. Use Grow through veg and switch to bloom through flower. If your plants look like they could use more or less just dial it in for your strain. Every three weeks during veg give a nitrogen boost and some food for your microbes by adding in a liquid fish fertilizer. Don't forget to test your feed PH. Liquid fish fertilizer is highly acidic, so much so, I use it for PH down during my whole veg cycle (I almost never need PH down).

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Fox Farm

The Fox Farm family of soils and fertilizers is by far the most common in the industry. They are very finicky and follow a feed schedule that's not the easiest to keep up with. But you really feel like you're doing something when you feed with this brand... because you do a lot. When you have it dialed in for your strain in your soil the results are miraculous! The rest of the time you'll see nutrient deficiencies and burn. I've included a feeding schedule below so you know what you're getting into. You don't need every product on the feeding schedule but you may need more than the trio to keep your plant happy. with some tracking you can achieve the highest quality results using the following five bottles.

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Additional Liquid Amendments

No mater what Liquid fertilizer brand or program you choose you'll want to have a couple of additional supplements on hand all the time.

• Super Thrive - ITS LITERALLY PLANT STEROIDS. You can't use this all the time or your plant may develop defects. It's a plant growth hormone derived from kelp mixed with some vitamins.

It' best used:

• • When you transfer to give your plants a boom. They'll blow past any transplant shock.

  • Anytime your plant is a little sick from a pest issue.

  • After you have corrected a nutrition deficiency or PH lockout and your plant is recovering from that stress.

• Cal-Mag (ideally with iron) should be added at every watering. There is some in tap water but none in RO or rain water and these plants need a fair amount. Adding some at every feeding is the best way to avoid the most common deficiency problems.

• A liquid form of silica that's totally bio-available. It strengthens cell walls and protects plants from stressful conditions. Its the main building block of trichomes. Every watering should start by adding this first. After 1 hour the rest of your nutrition can be added to the water. If you don't, the silica will cling to anything you add to the water and fall out of suspension where it wont help your plant. There is lots of silica in soil but the plant has to work to get it. This is available and ready to use so when your plant takes up water it gets this bonus silica it can use without processing. You'll see thicker stems and leaves and more trichome development than you have on any plants you weren't using this with.

After much side by side testing here are my top picks:

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Organic Dry Nutrients

Gaia Green

Hands down, my number one pick is the Gaia Green line up. They have it split into a general fertilizer for veg stage and a bloom fertilizer for flower stage. This isn't the easiest to get and you pay such a premium for it, that I don't use it myself. But I've seen the results you can get with it first hand and its very impressive.

Their 4-4-4- general fertilizer is made up of: Feather meal, alfalfa meal, bone meal, blood meal, glacial rock dust, natural rock phosphate, fishbone meal, mineralized phosphate, potassium sulphate, insect frass, basalt rock dust, humic acid, gypsum, kelp meal, oyster shell flour, and greensand. Its not cheap, but to get all these ingredients yourself in high quality forms and put them together in the right amounts. There is an Issue, the nitrogen count is low for cannabis but adding some 2-0-0 worm castings will get that value where it needs to be or water every two or so weeks with a liquid fish fertilizer.

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Down to Earth

My runner up pick is extremely strong and significantly more affordable for those of us in the US.

Their 4-4-4- general fertilizer is made up of: Fish Bone Meal, Alfalfa Meal, Feather Meal, Langbeinite, Basalt, Potassium Sulfate, Dolomite and Kelp Meal. There is an Issue, the nitrogen count is low for cannabis but adding some 2-0-0 worm castings will get that value where it needs to be or water every two or so weeks with a liquid fish fertilizer. Down to Earth did recognize this problem and put out a bat droppings amendment. It looks a little strong, I'd add it as a tea, as needed.

Their 4-8-4 Bloom fertilizer is made up of : Fish Bone Meal, Langbeinite, Blood Meal, Alfalfa Meal, Seabird Guano, Rock Phosphate, Humates and Kelp Meal. The only issue is, its a little low on potassium for cannabis so you'll have to add some.

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Co2 - For Big Dense Buds

Plants consume light, water, nutrition, and breath Co2 in a balance. So long as everything is in balance you're plant will be healthy. Raising Co2 levels doesn't do much for cannabis under normal indoor conditions. Its just one piece of the pie. The thing is, you can only raise every other piece so much before the bottle neck becomes Co2. If you want HUGE buds this is a big part of the trick. Raising the Co2 levels lets you increase the light intensity. Increased light requires increased water consumption for cooling. Increased water consumption brings increased nutrients for growing. To grow more than natural, the plant must breath more Co2 than is in the air. We've come full circle. Pumping up the Co2 lets you pump everything else up. If you pump up everything else beyond normal values without it you just burn or drown your plant.

The simplest way to raise the Co2 in your tent is a bag of fungus that grows in your tent and emits a whole lot of Co2 as a byproduct of digestion. Of course someone made this simple and got a self sustained mini ecosystem together in a bag just for you.

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Grow Mediums

Potting mix:

There are lots of options and each has pros and cons. I'm going to start with what I like to use and finish with what you should avoid.

Soilless & Semi soilless potting mix

These are top picks for weedgineering. They're either mostly peat moss or coco coir. I'm not a fan of peat moss because it shrinks significantly in size and becomes hydrophobic when it drys out. This causes it to cake up and water to simply run off the surface of it and down the sides of your pot or out of your fabric pots. Peat must be watered very slowly to get to to re-hydrate. Coco holds onto water like peat but when it dries it does not become hydrophobic so water will always flow right into it... no slow watering required.

I use Coco Loco by Fox farms. I chose it because it has high quality ingredients and isn't over fertilized like some fox farm products. When I build my own semi-soilless potting mix it ends up very similar to Coco Loco but costs me MORE to make. Plus, I never have as much diversity of ingredients.

Pro-mix is likely the most commonly used semi-soilless potting mix. I'm not a fan because its full of peat moss. Peat moss is very cheap so pro-mix can be assembled from scratch for just a buck or two per cubic foot. People like pro-mix for the blank canvas it provides. But if you're using it be sure to buy a bunch of extra fans to blow right on your pots to help the peat let go of some of that moisture. In my opinion there is never a reason to buy a bag of this when you can buy the stuff its made from at any hardware store way cheaper.

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Build your own living soil or semi soilless potting mix

Mix equal parts: Coco coir (sub peat moss if you need to), compost, and perlite. To this add mycorrhizae fungi and some worm castings. You can add all sorts of other amendments from bone meal to bat guano. But just these ingredients below will get you there. Anything else you add is gravy.

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Potting Soil

Most found at the the hardware store are terrible for indoor growing. These are almost all made of peat moss, compost, dirt, and a whole lot of wood bark / wood chips. The big problem is the peat moss and wood chips both hold a lot of water. This makes it hard for the potting soil to dry out which leads to fungus gnats and root rot. When it does dry out the peat moss becomes hydrophobic. I'm sure you've seen this with peat based potting soils. Water beads up and runs off the surface. You have to wet the peat moss and wood chips very very slowly for them to take up the water, then they're too wet again. Whenever possible skip these types of mixes all together. Instead get potting soil specialty made for growing cannabis like Fox Farms Ocean Forest and Happy Frog. These two products should be mixed together in equal parts for young plants and have everything needed to get you to flower phase. These are fantastic, combined they are probably the most commonly used potting soils for indoor weed grows. However, these aren't what I use. I use the semi-soilless potting mix coco loco or one I build myself as shown above.

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Potting Soil with long duration fertilizers

These have all the problems of regular potting soil with a whole new problem. There are nutrient granules with different coatings on them that look like little bead). The different coatings break down / dissolve in water at different rates over time. So a 6 month feed soil is going to have all the nutrients meant to break down and be delivered steady for 6 months. That's a fairly large problem for growing optimal cannabis. We need certain nutrients for the veg phase which is typically 1 to 3 months long and totally different values of those nutrients during the flower phase for the next 2 to 3 months. The slow release takes away your control. When you're trying to cut back nitrogen by switching to bloom nutrients. The soil is regularly dosing your plants with nitrogen so you end up with lots of very green leaves, small, and bad tasting buds. At the end of the grow, you would normally flush all nutrients out of the soil causing the plant to depleted its remaining nutrients resulting in much smoother tasting final product. But if you have slow release beads in your soil flushing with water just releases more nutrients. These types of soils are not good for cannabis and should be avoided. The only exception is bags that feed for two months or less.