Growing Hydroponic Marijuana – Basic Guide 1 & 2
HOW TO GROW HYDROPONIC MARIJUANA or WEED
Nutrients
Hydroponic plant food and solutions are measured in an N-P-K format on their labels. This stands for:
- N is Nitrogen
- P is Phosphorus
- K is Potassium
A 15-15-15 solution contains 15% Nitrogen, 15% Phosphorus, 15% Potassium. A 20-10-5 solution contains 20% Nitrogen, 10% Phosphorus, 5% Potassium. The percentage of the solution not used by N-P-K contains trace elements and inert material.
If you are buying hydroponic nutrient, get the powder kind that mixes with water. It is much cheaper over the long run when you compare it with already mixed solutions.
An all purpose hydroponic nutrient solution with secondary elements like calcium, sulphur and magnesium and trace elements boron, copper, molybdenum, zinc, iron, and manganese will get you through all stages of growth. But depending on the stage of growth, you can adjust different nutrient levels needed at different times to optimize growth.
- Higher amounts of N are needed when the temperature will be below 80 degrees in the grow room during vegetative growth stage. 20-20-20, or 23-19-17, or 12-6-6, or something similar, with trace elements should do it.
- If temperatures are higher than 80 degrees in the grow room, you usually need not worry about more N in the formula during vegetative growth.
- During flowering the plant needs lots of P, regardless of temperature. 15-30-15, or 5-20-10, or 2-4-3, or something similar, with trace elements should do it.
- Do not over fertilize your plants. Too much fertilizer will kill your plants. If you under fertilize, plants will take longer to grow but will not die. Follow the mixing instructions on your hydroponic solution package, if you aren’t sure, use less rather than more.
- As water evaporates and is absorbed by the plants, your reservoir level will drop. Add tap water that has been aged 3 days or longer to the reservoir. I don’t add nutrient solution when I top up the tank, some people do.
- Change the nutrient solution at least every 2 weeks. That is, discard the old solution and clean out the reservoir, pumps, and other equipment with HOT WATER. After cleaning, add tap water that has been aged 3 days or longer to the reservoir then add nutrient solution. You only need to clean the cups and tubing the plants are in before you start a new crop.
- The old solution that you are discarding can be used to water house or garden plants. This will at least double the growth rate if you usually water your plants with regular tap water. More detail on nutrients.
Marijuana nutrient cycle
Once the timer is set and it starts to pump the nutrient solution through to the plants it should submerge the roots and as soon as the roots are submerged, the pump should then shut down. You may either want to time this or use a mercury switch on a float to flip the pump off.
Check the root length every few weeks. If it is hard to remove the cups the plants are in because the roots are anchored to the internal channel, the roots are too long. The root should be short enough to not touch the narrow point where the solution enters the cup holder. If they are too long, trim them down with scissors. Make sure they are not going too far, but don’t cut unnecessarily. More detail on nutrients.
Harvesting and curing
Follow the harvesting directions located here and follow the curing directions click here.
Eliminating smell
Growing (and smoking) marijuana will produce odors. Sometimes they can be strong enough to attract attention. If you would like to eliminate the smell from growing and/or smoking marijuana the best thing to do is build an ozone generator. More detail on odor control.
Storing marijuana
If your weed is going to be stored for more than a year it should be wrapped in an air tight container and be stored somewhere that is dark and cool. A freezer is best, but a fridge, basement, closet, or something similar will do. Dry it first if you grow your own, or if the stuff you have is very moist. And remember that light, air and heat are the things to avoid.
“The best marijuana growing guide we have ever seen online, in our 15 years – Click here“
Industry Friends
Medical marijuana- Find out the truth about growing medical marijuana;
Marijuana seeds review - Seeds and seed banks reviewed;
Cannabis seeds – We trust our man Herbie to deliver your cannabis seeds anywhere in the world, fresh and discreetly;
LED grow lights – Broad (full) spectrum LED grow lights made by professionals and using the best LEDs available.
Latest forum topics
- Growing
Indoor grow under florescent tubes, garden No. 2
I’m using a couple T5 florescent tube lamps for my second grow. And holly cow, the girls are looking really good.
Take a look….
easy indoor please respond quickly
hello so i just got on here.. so i have a bathroom thats about 4 feet buy 4 feet and 6 and a half feet tall… i took out the toilet and sink…. so…
Can you transfer a month old plant in soil, to a hydroponic system?
Can you transfer a month old plant in soil, to a hydroponic system?
New to Growing looking for advice on setup
I have a 6’8 tall by 2 feet by 1 1/2 foot closet space I am willing to start trying to grow a plant indoors for personal use. Can anyone help me out…
Problem with plants
I’m a fairly seasoned grower but have run into a problem I can’t seem to fix. My plants are defoliating a little at a time. They start off looking…

