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Hydroponic Grow Room

Space for a Grow Room - If the Grow Room is intended for Medical Marijuana or Hemp CBD, each plant when full grown, should be as high as six foot tall and a diameter of about 4 feet. If the limit is six plants, so the total space needed is about a ten foot by ten foot room. This would also be the amount of space needed in a garage. Forget about growing in a closet unless you have a really big closet.

If you have access to a greenhouse, this would be an ideal grow room because there is not much need for lighting.

Rules in your area may require an indoor grow room with a locked door. If the room is in a home that has heat and air conditioning into the room, it already has some of the important parts of climate control handled.

Components for a Grow Room

  • 1.Seed Starter system $6.00
  • 2. Six 5 gallon Containers $18.00
  • 3. Six 3/8" nylon adapter fittings $4.00
  • 4. Perlite substrate 4 cubic foot bag $20.00
  • 5. 32 Gallon plastic garbage can $20
  • 6. Hydroponic Nutrients Grow and Bloom $400 to 600
  • 7. Grow Lights $300
  • 8. Timer $40
  • 9. Oscillating Fan $40
  • 10. Temperature - humidity meter $10
  • 11. PH paper $2
  • 12. Pruners $6
  • 13. Watering Can $6
  • 14. Spray bottles $2
The recommended system costs slightly under $1000 to purchase. This does not include components needed for climate control.

1. Seed Starter System

There are two basic methods of obtaining new plants. One is to obtain seeds and plant them in aseedling grower.

Libby makes a complete seedling tray with grow plugs and a plastic cover. These run about $6.00 at Walmart.

2.Growing Containers

To accommodate plants that may reach six foot tall and four foot daimeters, you will need a larger container. I use 5 gallon plastic containers, and add a drain hole on the side.

3. 3/8 threaded nulon adapter fillings

I drill a 3/8" hole about 2 inches from the bottom, and then screw in a 3/8" plastic fitting. There are a few options for these fittings, but I use the 3.8 inch straight fittings. The reason to do this is that the container will then have a reserve of water in the container that will keep the plant with a water supply in between waterings.

The container has a drain hole so excess water can go out that drain hole onto the surface below. A catch basin will need to be under each plant such as a tray sold in nursey stores, or a cheaper clear plastic. The drains can be fitted with plastic hose that gathers the water in a container, or drains it outside.

4. Perlite Substrate

There are many types of substrate that can used in place of soil. I prefer using perlite, which is pieces of volcanic obsidian that have been expanded by being popped in a kiln. The perlite is white in appearance and usuallly comes in two grades, propoagtion and construction. The propagation should be small pieces, like small pebbles, If the perlite is fine dust it is construction grade, and will not work in hydroponics. The reasons that perlite works so well is that it has a neutral pH, and tends to stay that way, it relatively light, but not so light it will blow away. It wicks water so that water in the bottom of the container trickles up towards the top. It is a long standing substrate used in hydroponics that has weathered the test of time. It is also inexpensive. A four cubic foot bag should be available at a nursery supply store for about $16.00 and that should be enough for your six 5 gallon growing containers.

5. 32 gallon Garbage Can - Nutrient Water container

The water to be used for the plants should be in a container. This should be from 30 to 50 gallon container such as a plastic garbage container with a cover. The water can be tap water, or harvested rainwater. Once the water is in the container, hydroponic nutrient can be added to the water. This is then used to give nutrient water to the plants every day. Ths can be done by dipping in a watering can and watering by hand, or to supply an automatic watering system.

6. Hydroponic Nutrients

There are many commercial hydroponic nutrients on the market. Many sell for about $80.00 a gallon, and they are added to the waterat the rate offone teaspoon per gallon. There are about 768 teaspoons in a gallon so that should provide about 768 gallons of nutrient water. Each day the 32 gallon garbage can should be filled with water and then about 2/3 of a cup of hydroponic nutrient added. Or if not using ours, follow instructions on nutrient container.

Watering Plants

Each plant picks up water from its roots, distributes it through the plant, and then water is transpired from the plants leaves. A plant will transpire more water when it is too hot, to cool its leaves and so a plant can use twice as much water on a hot day. So if your plants are in a place where the climate is not controlled, they will need y=twice as much water on a hot day and that water needs to be diluted with half as much nutrient.

Amount of water used according to plant age.

  • Seedlings - 1/4 to 1/2 gallon.
  • Younger Plants - 1/2 to 1 gallon.
  • Mid zize or half grown = 1 to 2 gallons for a plant up to 4 feet diameter.
  • Flowering - 1 to 3 gallons for plants with a canopy of up to 4 feet diameter. when imdoors
  • Flowering outdoors - up to 6 gallons of water

For the grow room of six seedlings, six mid range and six flowering plants, the amount of water required is likely to be about 32 gallons of water.

7. Grow lights

The indoor grow room needs lights for the plants.

A T5 Florescent light fixture

The seedlings and small plants up to about a six inches tall can be grown under T5 florescent lights. These lights are usually hung about a foot above the growing plants and are sufficient to keep the young plants healthy and growing.

After the plants are about a foot tall, they will need more light that is offered from the T5, so the T5 light is pretty much allocated to the young plants.

Larger plants will need a stronger light, and in the year 2019, there is a raging controversy about our new LED lights. The tradition is to use a high pressure sodium, and metal halide light to grow plants.

A HID Light

A suitable light is a high intensity discharge(HID). Check out the LEC 315 3100K units.

LED Grow Light

A LED light fixture for a 3 by 3 foot growing area

There are now growlights in LED. The pictured light covers a three by three foot area, so it services one full size plant. There are LED lights for about $140 to $180 that have good reviews, but there are also disappontments.

WE have ome successful grow room that used T5 and LED in the ceiling and was able to raise wonderful plants.

in led plants need at 32w of actual power per square meter.For six plants 192 watts are needed.

LED lights have a limitation in the grow light spectrum they emit. That is why most LED grow light have three colors of red blue and white. That combination gives a still limited lighy sprectrum that canbe limiting to plants.

5. Timer

Timers are used to turn lights or watering systems on and off.

The plants need at least a 12 hour day and can handle 18 hours. Fourteen hours is probably ideal. The timer then automatically turns the grow light on and off at a set times.

Timers can be a simple ten dollar device for one item or a complcated device for multiple devices.

6. Rotating / Oscilating Fan

Rotating fans circulate air in your grow room preventing mold growth. Use an oscillating fan mounted to the wall.

9. Thermometer humidity meter

This meter measures temperature and humidity inside the grow room.

10. pH paper

The hydroponics works best when the pH of the system is between 5.5 and 6.5 pH. This can be checked with pH test strip papers in this range.

11. Pruners

Pruners are used to trim plants or harvest part of a live plant. They should be left in Growroom to prevent contamination.

12. Watering Can

I use plastic watering cans for the hydroponic nutrient. Metal cans can react with the nutrient water.

Automatic Watering system Battery powered water pump. This with a timer allows for nutrient water to be automatically pumped a few times a day. We have an article on Setting up a DC battery watering system.

13. Spray Bottles

Spray bottles are usd for pest control (garlic red pepper spray) and for spraying nutrient water on the plants. Marijuana can obtain some of its nutrients through the leaves.

Climate controlled

On this topic, the plants breathe in carbon dioxide and breath out oxygen. There is very little carbon dioxide in the atmosphere 0.04% carbon dioxide. So the plants will quickly use the cu2 in an enclosed room. If there is not either an air exchange or co2 supplimented in the room the plants will soon quit growing and then die.

Air exchange

Ventilation means that air has to be blown into the room and allowed to blow out. This will also help with the excess humidity in the room.

Vent

In a greenhouse, a top opening vent maybe enough to allow air to exit, removing excess humidity and in some cases, excess heat. in our family greenhouse, we use a fan that is attached to a solr cell. The fan is located near the floor and it is set to bring air in from the outside. The fan uses when the solar cell sees sun, so it works well on sunny days.

Climate control

Temperature Range

The ideal temperature range for marijuana is from 70 to 80 degrees F. It may be necessary to install an air conditioner in a window that has a temperature set point. Probably set it for 76 to 78 degrees.

The air conditioner is also helpful in dealing with the humidity in the room .

Humidity

When you have a plant room using 35 gallons of water a day the humidity will increase. So this means the humidity, or water in the air, will quickly and a form of expelling water out of the grow room is essential. The ideal humidity for growing plants is betwen 40 and 50% Seedlings like a higher humidity of about 65% and this can be obtained by leaving the p clear plastic tp on the seedling grower until the plants have a second set of leaves.

Humidity Control

Maintaining the 40 to 50% humidity requires both a humidifier and a dehumidifier in the room. The air conditioner will help, but is likely not enough for real control.

Carbon Dioxide

Plants breathe in carbon dioxide and breath out oxygen. There is very little carbon dioxide in the atmosphere 0.04% carbon dioxide which is about 400 parts per million (ppm). The plants can grow fine on 400 ppm and would grow even better at 1000 ppm.

The problem wih CO2 is that there is very little in the atmosphere, and the plants will quickly use up the CO2 in an enclosed room.

So the plants will quickly use the CO2 in an enclosed room. If there is not either an air exchange or co2 supplimented in the room the plants will soon quit growing and then die.

When CO2 is added to the room with CO2 tanks, the cost is expensive, with costs reaching $50 for the CO2 refills, and the difficulty of taking the tanks to a place to refill.

When a tank of CO2 is used, ut should not be used in the nighttime as plants do not need it if not in the lihght.

Air exchange

The easiest option for keeping the plants in CO@ is to ventilate the room, bringing fresh air in and exhausting stake air out.

Vent

In a greenhouse, a top opening vent maybe enough to allow air to exit, removing excess humidity and in some cases, excess heat. in our family greenhouse, we use a fan that is attached to a solr cell. The fan is located near the floor and it is set to bring air in from the outside. The fan uses when the solar cell sees sun, so it works well on sunny days.

Ventilation in an enclosed room means that a vent may have to be cut into the exterior wall, like a clothes drier vent, And a fan is placed in a window that pulls air into the room.

Energy Costs

The grow room will have monthly energy costs that may reach $59 a month. The LEd and T5 lights take less energy than the HID lights and do not emit so much heat.

Rhe HID lights run hot and can cause a fire if placed too close to something that can burn.