Hydroponic Systems

BobNarley · 05-28-2008, 01:11 PM

Hydroponic Systems
PASSIVE HYDROPONIC SYSTEMS

Most hydroponic systems fall into one of two broad categories:
passive or active. Passive systems such as reservoir or wick setups
depend on the molecular action inherent in the wick or medium to
make water available to the plant. Active systems which include the
flood, recirculating drip and aerated water systems, use a pump to
send nourishment to the plants.
Most commercially made "hobby" hydroponic systems
designed for general use are shallow and wide, so that an intensive
garden with a variety of plants can be grown. But most marijuana
growers prefer to grow each plant in an individual container.

The Wick System
The wick system is inexpensive, easy to set up and easy to
maintain. The principle behind this type of passive system is that a
length of 3/8 to 78 inch thick braided nylon rope, used as a wick, will
draw water up to the medium and keep it moist. The container,
which can be an ordinary nursery pot, holds a rooting medium and
has wicks running along the bottom, drooping through the holes at
the bottom, reaching down to the reservoir. Keeping the holes in the
container small makes it difficult for roots to penetrate to the reser-
voir. The amount of water delivered to the medium can be increas-
ed by increasing the number, length, or diameter of the wicks in
contact with the medium.
A 1 gallon container needs only a single wick, a three gallon
container should have two wicks, a five gallon container, three
'wicks. The wick system is self-regulating; the amount of water
delivered depends on the amount lost through evaporation or
transpiration.

Each medium has a maximum saturation level. Beyond that
point, an increase in the number of wicks will not increase the
moisture level. A 1-1-I combination of vermiculite, perlite, and
styrofoam is a convenient medium because the components are
lightweight and readily available. Some commercial units are sup-
plied with coarse vermiculite. To increase weight so that the plant
will not tip the container over when it gets large, some of the perlite
in the recipe can be replaced with sand. The bottom inch or two of
the container should be filled only with vermiculite, which is very
absorbent, so that the wicks have a good medium for moisture
transfer.
Wick systems are easy to construct. The wick should extend S
inches or more down from the container. Two bricks, blocks of
wood, or styrofoam are placed on the bottom of a deep tray (a
plastic tray or oil drip pan will do fine.) Then the container is placed
on the blocks so that the wicks are touching the bottom of the tray.
The tray is filled with a nutrient/water solution. Water is replaced
in the tray as it evaporates or is absorbed by the medium through
the wick.
A variation of this system can be constructed using an addi-
tional outer container rather than a tray. With this method less
water is lost due to evaporation.
To make sure that the containers fit together and come apart
easily, bricks or wood blocks are placed in the bottom of the outer
container. The container is filled with the nutrient/water solution
until the water comes to just below the bottom of the inner con-
tainer.
Automating this system is simple to do. Each of the trays or
bottom containers is connected by tubing to a bucket containing a
float value such as found in toilets. The valve is adjusted so that it
shuts off when the water reaches a height about 1/2 inch below the
bottom of the growing containers. The bucket with the float valve is
connected to a large reservoir such as a plastic garbage can or 55
gallon drum. Holes can be drilled in the containers to accomodate
the tubing required, or the tubes can be inserted from the top of the
containers or trays. The tubes should be secured or weighted down
so that they do not slip out and cause floods.
The automated wick system works as a siphon. To get it
started, the valve container is primed and raised above the level of
the individual trays. Water flows from the valve to the plant trays as
a result of gravity. Once the containers have filled and displaced air
from the tubes, the water is automatically siphoned and the valve
container can be lowered. Each container receives water as it needs
it.
A simpler system can be devised using a plastic kiddie pool and
some 4 x 4's or a wooden pallet. Wood is placed in the pool so that
the pots sit firmly on the board; the pool is then filled with water up
to the bottom of the pots. The wicks move the water to the pots.
Wick systems and automated wick systems are available from
several manufacturers. Because they require no moving parts, they
are generally reliable although much more expensive than

homemade ones, which are very simple to make.
Wick system units can be filled with any of the mixes found in
Chart 7-1-A.

The Reservoir System
The reservoir system is even less complex than the wick system.
For this setup all a grower needs to do is fill the bottom 2 or 3 inches
of a 12 inch deep container with a coarse, porous, inert medium
such as lava, ceramic beads or chopped unglazed pottery. The re-
maining portion is filled with one of the mixes containing
styrofoam. The container is placed in a tray, and sits directly in a
nutrient-water solution 2-3 inches deep. The system is automated
by placing the containers in a trough or large tray. Kiddie pools can
aiso be used. The water is not replaced until the holding tray dries.
Passive systems should be watered from the top down once a
month so that any buildup of nutrient salts caused by evaporation
gets washed back to the bottom.
ACTIVE HYDROPONIC SYSTEMS

Active systems move the water using mechanical devices in
order to deliver it to the plants. There are many variations on active
systems but most of them fall into one of three categories: flood
systems, drip systems or nutrient film systems.

The Flood System
The flood system is the type of unit that most people think of
when hydroponics is mentioned. The system usually has a reservoir
which periodically empties to flood the container or tub holding the
medium. The medium holds enough moisture between irrigations to
meet the needs of the plant. Older commercial greenhouses using
this method often held long troughs or beds of gravel. Today, flood
systems are designed using individual containers. Each container is
attached to the reservoir using tubing.
A simple flood system can be constructed using a container
with a tube attached at the bottom of a plastic container and a jug.
The tube should reach down to the jug, which should be placed
below the bottom of the growing container. To water, the tube is
held above the container so that it doesn't drip. The water is poured
from the jug into the container. Next, the tube is placed in the jug
and put back into position, below the growing container. The water
will drain back into the jug. Of course, not as much will drain back
in as was poured out. Some of the water was retained in the growing
unit.
Automating this unit is not difficult. A two-holed stopper is
placed in the jug. A tube from the growing unit should reach the

bottom of the reservoir container. Another tube should be attached
to the other stopper hole and then to a small aquarium-type air
pump which is regulated by a timer. When the pump turns on, it
pushes air into the jug, forcing the water into the container. When
the pump goes off, the water is forced back into the jug by gravity.
Several growing units can be hooked up to a large central reservoir
and pump to make a larger system. The water loss can automatical-
ly be replaced using a float valve, similar to the ones used to
regulate water in a toilet. Some growers place a second tube near
the top of the container which they use as an overflow drain.
Another system uses a reservoir above the growing container
level. A water timing valve or solenoid valve keeps the water in the
reservoir most of the time. When the valve opens, the water fills the
growing containers as well as a central chamber which are both at
the same height. The growing chambers and the central chamber
are attached to each other. The water level is regulated by a float
valve and sump pump. When the water level reaches a certain
height, near the top of the pots, the sump pump automatically turns
on and the water is pumped back up to the reservoir.
One grower used a kiddie pool, timer valve, flower pots, a rais-
ed reservoir and sump pump. He placed the containers in the kiddie
pool along with the sump pump and a float valve. When the timer
valve opened, the water rushed from the tank to the kiddie pool,
flooding the containers. The pump turned on when the water was
twb inches from the top of the containers and emptied the pool.
Only when the valve reopened did the plants receive more water.
With this system, growers have a choice of mediums, including
sand, gravel, lava, foam or chopped-up rubber. Vermiculite,
perlite, and styrofoam are too light to use. The styrofoam and
perlite float, and the vermiculite becomes too soggy.
The plants' water needs to increase during the lighted part of
the daily cycle, so the best time to water is as the light cycle begins.
If the medium does not hold enough moisture between waterings,
the frequency of waterings is increased.
There are a number of companies which manufacture flood
systems. Most of the commercially made ones work well, but they
tend to be on the expensive side. They are convenient though.
The Drip System
Years ago, the most sophisticated commercial greenhouses
used drip emitter systems which were considered exotic and
sophisticated engineering feats. These days, gardeners can go to any
well-equipped nursery and find all of the materials necessary to
design and build the most sophisticated drip systems. These units
consist of tubing and emitters which regulate the amount of water
delivered to each individual container. Several types of systems can
he designed using these devices.
The easiest system to make is a non-return drain unit. The
plants are watered periodically using a diluted nutrient solution. Ex-
cess water drains from the containers and out of the system. This
System is only practical when there is a drain in the growing area. If

each container has a growing tray to catch excess water and the
water control valve is adjusted closely, any excess water can be held
in the tray and eventually used by the plant or evaporated. Once a
gardener gets the hang of it, matching the amount of water
delivered to the amount needed is easy to do.
One grower developed a drip emitter system which re-uses the
water by building a wooden frame using 2 x 4's and covering it with
corrugated plastic sheeting. She designed it so that there was a slight
slope. The containers were placed on the corrugated plastic, so the
water drained along the corrugations into a rain drainage trough,
which drained into a 2 or 3 gallon holding tank. The water was
pumped from the holding tank back to the reservoir. The water was
released from the reservoir using a timer valve.
Growers make sure to use self-cleaning drip emitters so that
they do not clog with salt deposits. About a gallon every six hours
during daylight hours is pumped. Drip emitters can be used with
semiporous mediums such as ceramic beads, lava, gravel, sand or
periite-vermiculite-styrofoam mixtures.
Aerated Water
The aerated water system is probably the most complex of the
hydroponic systems because it allows the least margin for error. It
should only be used by growers with previous hydroponic ex-
perience. The idea of the system is that the plant can grow in water
as long as the roots receive adequate amounts of oxygen. To pro-
vide the oxygen, an air pump is used to oxygenate the water through
bubbling and also by increasing the circulation of the water so that
there is more contact with air. The plants can be grown in in-
dividual containers, each with its own bubbler or in a single flooded
unit in which containers are placed. One grower used a vinyl-
covered tank he constructed. He placed individual containers that
he made into the tank. His containers were made of heavy-duty
nylon mesh used by beermakers for soaking hops. This did not pre-
vent water from circulating around the roots.
Aerated water systems are easy to build. A small aquarium air
pump supplies all the water that is required. An aerator should be
connected to the end and a clear channel made in the container for
the air. The air channel allows the air to circulate and not disturb
the roots. Gravel, lava, or ceramic is used.
Nutrient Film Technique
The nutrient film technique is so named because the system
creates a film of water that is constantly moving around the roots
This technique is used in many commercial greenhouses to cultivate ~
fast growing vegetables such as lettuce without any medium. The
plants are supported by collars which hold them in place. This
method is unfeasible for marijuana growers. However, it can be
modified a bit to create an easy4o-care-for garden. Nursery sup-
pliers sell water mats, which disperse water from a soaker hose to a
nylon mat. The plants grow in bottomless containers which sit on
the mat. The medium absorbs water directly from the mat. In order

to hold the medium in place, it is placed in a nylon net bag in the
container.

05-28-2008, 01:11 PM	#1 (permalink)
BobNarley My Mood: Join Date: May 2007 Location: Mojove Desert-Southern California Posts: 530 gRamz: 13,372 Danks: 26 Danked 17 Times in 14 Posts	Hydroponic Systems Hydroponic Systems PASSIVE HYDROPONIC SYSTEMS Most hydroponic systems fall into one of two broad categories: passive or active. Passive systems such as reservoir or wick setups depend on the molecular action inherent in the wick or medium to make water available to the plant. Active systems which include the flood, recirculating drip and aerated water systems, use a pump to send nourishment to the plants. Most commercially made "hobby" hydroponic systems designed for general use are shallow and wide, so that an intensive garden with a variety of plants can be grown. But most marijuana growers prefer to grow each plant in an individual container. The Wick System The wick system is inexpensive, easy to set up and easy to maintain. The principle behind this type of passive system is that a length of 3/8 to 78 inch thick braided nylon rope, used as a wick, will draw water up to the medium and keep it moist. The container, which can be an ordinary nursery pot, holds a rooting medium and has wicks running along the bottom, drooping through the holes at the bottom, reaching down to the reservoir. Keeping the holes in the container small makes it difficult for roots to penetrate to the reser- voir. The amount of water delivered to the medium can be increas- ed by increasing the number, length, or diameter of the wicks in contact with the medium. A 1 gallon container needs only a single wick, a three gallon container should have two wicks, a five gallon container, three 'wicks. The wick system is self-regulating; the amount of water delivered depends on the amount lost through evaporation or transpiration. Each medium has a maximum saturation level. Beyond that point, an increase in the number of wicks will not increase the moisture level. A 1-1-I combination of vermiculite, perlite, and styrofoam is a convenient medium because the components are lightweight and readily available. Some commercial units are sup- plied with coarse vermiculite. To increase weight so that the plant will not tip the container over when it gets large, some of the perlite in the recipe can be replaced with sand. The bottom inch or two of the container should be filled only with vermiculite, which is very absorbent, so that the wicks have a good medium for moisture transfer. Wick systems are easy to construct. The wick should extend S inches or more down from the container. Two bricks, blocks of wood, or styrofoam are placed on the bottom of a deep tray (a plastic tray or oil drip pan will do fine.) Then the container is placed on the blocks so that the wicks are touching the bottom of the tray. The tray is filled with a nutrient/water solution. Water is replaced in the tray as it evaporates or is absorbed by the medium through the wick. A variation of this system can be constructed using an addi- tional outer container rather than a tray. With this method less water is lost due to evaporation. To make sure that the containers fit together and come apart easily, bricks or wood blocks are placed in the bottom of the outer container. The container is filled with the nutrient/water solution until the water comes to just below the bottom of the inner con- tainer. Automating this system is simple to do. Each of the trays or bottom containers is connected by tubing to a bucket containing a float value such as found in toilets. The valve is adjusted so that it shuts off when the water reaches a height about 1/2 inch below the bottom of the growing containers. The bucket with the float valve is connected to a large reservoir such as a plastic garbage can or 55 gallon drum. Holes can be drilled in the containers to accomodate the tubing required, or the tubes can be inserted from the top of the containers or trays. The tubes should be secured or weighted down so that they do not slip out and cause floods. The automated wick system works as a siphon. To get it started, the valve container is primed and raised above the level of the individual trays. Water flows from the valve to the plant trays as a result of gravity. Once the containers have filled and displaced air from the tubes, the water is automatically siphoned and the valve container can be lowered. Each container receives water as it needs it. A simpler system can be devised using a plastic kiddie pool and some 4 x 4's or a wooden pallet. Wood is placed in the pool so that the pots sit firmly on the board; the pool is then filled with water up to the bottom of the pots. The wicks move the water to the pots. Wick systems and automated wick systems are available from several manufacturers. Because they require no moving parts, they are generally reliable although much more expensive than homemade ones, which are very simple to make. Wick system units can be filled with any of the mixes found in Chart 7-1-A. The Reservoir System The reservoir system is even less complex than the wick system. For this setup all a grower needs to do is fill the bottom 2 or 3 inches of a 12 inch deep container with a coarse, porous, inert medium such as lava, ceramic beads or chopped unglazed pottery. The re- maining portion is filled with one of the mixes containing styrofoam. The container is placed in a tray, and sits directly in a nutrient-water solution 2-3 inches deep. The system is automated by placing the containers in a trough or large tray. Kiddie pools can aiso be used. The water is not replaced until the holding tray dries. Passive systems should be watered from the top down once a month so that any buildup of nutrient salts caused by evaporation gets washed back to the bottom. ACTIVE HYDROPONIC SYSTEMS Active systems move the water using mechanical devices in order to deliver it to the plants. There are many variations on active systems but most of them fall into one of three categories: flood systems, drip systems or nutrient film systems. The Flood System The flood system is the type of unit that most people think of when hydroponics is mentioned. The system usually has a reservoir which periodically empties to flood the container or tub holding the medium. The medium holds enough moisture between irrigations to meet the needs of the plant. Older commercial greenhouses using this method often held long troughs or beds of gravel. Today, flood systems are designed using individual containers. Each container is attached to the reservoir using tubing. A simple flood system can be constructed using a container with a tube attached at the bottom of a plastic container and a jug. The tube should reach down to the jug, which should be placed below the bottom of the growing container. To water, the tube is held above the container so that it doesn't drip. The water is poured from the jug into the container. Next, the tube is placed in the jug and put back into position, below the growing container. The water will drain back into the jug. Of course, not as much will drain back in as was poured out. Some of the water was retained in the growing unit. Automating this unit is not difficult. A two-holed stopper is placed in the jug. A tube from the growing unit should reach the bottom of the reservoir container. Another tube should be attached to the other stopper hole and then to a small aquarium-type air pump which is regulated by a timer. When the pump turns on, it pushes air into the jug, forcing the water into the container. When the pump goes off, the water is forced back into the jug by gravity. Several growing units can be hooked up to a large central reservoir and pump to make a larger system. The water loss can automatical- ly be replaced using a float valve, similar to the ones used to regulate water in a toilet. Some growers place a second tube near the top of the container which they use as an overflow drain. Another system uses a reservoir above the growing container level. A water timing valve or solenoid valve keeps the water in the reservoir most of the time. When the valve opens, the water fills the growing containers as well as a central chamber which are both at the same height. The growing chambers and the central chamber are attached to each other. The water level is regulated by a float valve and sump pump. When the water level reaches a certain height, near the top of the pots, the sump pump automatically turns on and the water is pumped back up to the reservoir. One grower used a kiddie pool, timer valve, flower pots, a rais- ed reservoir and sump pump. He placed the containers in the kiddie pool along with the sump pump and a float valve. When the timer valve opened, the water rushed from the tank to the kiddie pool, flooding the containers. The pump turned on when the water was twb inches from the top of the containers and emptied the pool. Only when the valve reopened did the plants receive more water. With this system, growers have a choice of mediums, including sand, gravel, lava, foam or chopped-up rubber. Vermiculite, perlite, and styrofoam are too light to use. The styrofoam and perlite float, and the vermiculite becomes too soggy. The plants' water needs to increase during the lighted part of the daily cycle, so the best time to water is as the light cycle begins. If the medium does not hold enough moisture between waterings, the frequency of waterings is increased. There are a number of companies which manufacture flood systems. Most of the commercially made ones work well, but they tend to be on the expensive side. They are convenient though. The Drip System Years ago, the most sophisticated commercial greenhouses used drip emitter systems which were considered exotic and sophisticated engineering feats. These days, gardeners can go to any well-equipped nursery and find all of the materials necessary to design and build the most sophisticated drip systems. These units consist of tubing and emitters which regulate the amount of water delivered to each individual container. Several types of systems can he designed using these devices. The easiest system to make is a non-return drain unit. The plants are watered periodically using a diluted nutrient solution. Ex- cess water drains from the containers and out of the system. This System is only practical when there is a drain in the growing area. If each container has a growing tray to catch excess water and the water control valve is adjusted closely, any excess water can be held in the tray and eventually used by the plant or evaporated. Once a gardener gets the hang of it, matching the amount of water delivered to the amount needed is easy to do. One grower developed a drip emitter system which re-uses the water by building a wooden frame using 2 x 4's and covering it with corrugated plastic sheeting. She designed it so that there was a slight slope. The containers were placed on the corrugated plastic, so the water drained along the corrugations into a rain drainage trough, which drained into a 2 or 3 gallon holding tank. The water was pumped from the holding tank back to the reservoir. The water was released from the reservoir using a timer valve. Growers make sure to use self-cleaning drip emitters so that they do not clog with salt deposits. About a gallon every six hours during daylight hours is pumped. Drip emitters can be used with semiporous mediums such as ceramic beads, lava, gravel, sand or periite-vermiculite-styrofoam mixtures. Aerated Water The aerated water system is probably the most complex of the hydroponic systems because it allows the least margin for error. It should only be used by growers with previous hydroponic ex- perience. The idea of the system is that the plant can grow in water as long as the roots receive adequate amounts of oxygen. To pro- vide the oxygen, an air pump is used to oxygenate the water through bubbling and also by increasing the circulation of the water so that there is more contact with air. The plants can be grown in in- dividual containers, each with its own bubbler or in a single flooded unit in which containers are placed. One grower used a vinyl- covered tank he constructed. He placed individual containers that he made into the tank. His containers were made of heavy-duty nylon mesh used by beermakers for soaking hops. This did not pre- vent water from circulating around the roots. Aerated water systems are easy to build. A small aquarium air pump supplies all the water that is required. An aerator should be connected to the end and a clear channel made in the container for the air. The air channel allows the air to circulate and not disturb the roots. Gravel, lava, or ceramic is used. Nutrient Film Technique The nutrient film technique is so named because the system creates a film of water that is constantly moving around the roots This technique is used in many commercial greenhouses to cultivate ~ fast growing vegetables such as lettuce without any medium. The plants are supported by collars which hold them in place. This method is unfeasible for marijuana growers. However, it can be modified a bit to create an easy4o-care-for garden. Nursery sup- pliers sell water mats, which disperse water from a soaker hose to a nylon mat. The plants grow in bottomless containers which sit on the mat. The medium absorbs water directly from the mat. In order to hold the medium in place, it is placed in a nylon net bag in the container.

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