CropKing NFT 4-6

(10ft) 1/2” Hoseitem HOS0500

Greenback Valveitem EMI1014

Variflo Valveitem EMI1015

Route The White Feed Tube Into The Top CoverOf The Channel ( 1 per channel ) and onto the valve, Be sure it seats all the way down,If you have leaks it might needpushed on further.

1/2" Hose

Ziptie the feed line to the frame

112015

NFT 4-6Feed Tube

R

Punch Tool Emitter Nipple

1. 2. 3.

Install Here

Punch a hole for each channel intothe 1/2" hose using the punch tool

Insert 1 Variflow valve into the 1/2" hose.

Install the Greenback Valve onto the endof the hose.

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Growing and Operation Guidelines

for Small-Scale CropKing NFT Systems

Welcome to soilless agriculture!

We at CropKing are excited that you have chosen to take a trip into the fabulous world of hydroponics with

us. We want you to know that your success in your new vegetable venture is our highest priority and the

central goal of this manual.

The word hydroponics literally means “working water.” Instead of depending on the soil to provide or hold

needed nutrients, fertilizers are completely dissolved in water in these systems and circulated past the plant

roots. In the most specific use of the word, hydroponics is carried out without a support media for the plants.

However, we will generally refer to hydroponics by the broader term of soilless crop production. Soilless

production is carried out with a variety of media to provide plant support including rockwool, perlite, coconut

coir, and peat. Regardless of what materials we are using, the main premise remains the same. Essentially we

are ‘cutting out the middle man’, which is that soil-water-plant interaction and providing all the plant needs

right in the nutrient solution. This controlled method of production means that the delivery of nutrients can

be tailored for optimum plant growth and productivity.

There are three key components that will enable you to successfully grow fresh produce in this soilless

system. In this instruction manual, we would like to present you with some important facts and key steps in

bringing together these three components- the growing system, the nutrient solution, and the plant itself.

Understanding the management of each will be important in producing a successful crop.

1. The Growing System- Nutrient Film Technique (NFT) and Materials

NFT is a solution culture system where the plant roots are directly bathed in flowing nutrient solution. The

NFT system is constructed of a steel or aluminum support system that holds rows of food-grade PVC channels.

There is a small stream of nutrient rich water (the film) continually flowing along the bottom of the channel.

This thin flow of solution (called a film) delivers the needed nutrients to the root of the plants while also

optimizing the oxygen available to the root zone. The CropKing NFT growing channels have removable top

caps for easy cleaning. These plastic top caps have specially sized holes punched for the plants at optimum

spacing for bibb or romaine lettuce heads to mature. Irrigation lines run from the nutrient tank and the

solution is delivered by a submersible or extern

rates of nutrient solution in the 8 to 10 ounces per minute range are appropriate.

covered and fit directly into the drain line

nutrient solution and promoting algae growth.

The nutrient solution is being constantly

reservoir under the channel allows for gravity return of the nutrient sol

the channels. Because of the short duration

recirculated solution can be used for the NFT.

closed system also conserves the nutrient solution

is from transpiration from the plant leave

Mixed lettuce growing in a CropKing channel in

The NFT method is typically used for the production of small leaf

have a shorter growing season than tomato or peppers. Lettuce, herb

directly into 1” Grodan rockwool cubes or other cubes or plugs composed of po

(shredded husks). These small cubes provide

an excellent environment to start and grow the young plants. Rockwool is actually

heated to extremely high temperatures. This high heat melts the rock

fibers which are shaped into the rockwool cubes. Rockwool works well for hydroponics because

or external pump to each individual channel using a small feed line.

rates of nutrient solution in the 8 to 10 ounces per minute range are appropriate. The ends of the channels are

covered and fit directly into the drain line to maintain a closed system to prevent light from contacting the

algae growth.

constantly re-circulated between the nutrient tank and the channel

allows for gravity return of the nutrient solution and it is then pumped back up to

. Because of the short duration (6 to 8 weeks) of the crop and the fact that it is vegetative

recirculated solution can be used for the NFT. However constant monitoring is needed as discussed below

closed system also conserves the nutrient solution by greatly reducing evaporation, so most of the water loss

leaves.

ettuce growing in a CropKing channel in an NFT system.

sed for the production of small leafy crops such as lettuce and herbs which

have a shorter growing season than tomato or peppers. Lettuce, herbs, and other leafy crops are seeded

directly into 1” Grodan rockwool cubes or other cubes or plugs composed of polymers, peat and coconut coir

(shredded husks). These small cubes provide consistent moisture for the germinating seed

an excellent environment to start and grow the young plants. Rockwool is actually basalt

xtremely high temperatures. This high heat melts the rock and the molten material is used to form

into the rockwool cubes. Rockwool works well for hydroponics because

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to each individual channel using a small feed line. Flow

The ends of the channels are

light from contacting the

circulated between the nutrient tank and the channels. The

and it is then pumped back up to

and the fact that it is vegetative, a

However constant monitoring is needed as discussed below. The

so most of the water loss

NFT system.

crops such as lettuce and herbs which

and other leafy crops are seeded

lymers, peat and coconut coir

germinating seed and also provides

basalt rock that has been

and the molten material is used to form

into the rockwool cubes. Rockwool works well for hydroponics because even when

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saturated with water, it has a high level of aeration. Additionally, it interacts little with the nutrient solution so

precise control over the solution that comes in contact with the roots is possible.

A sheet of rockwool cubes that can be used to seed

leafy crops for production in an NFT system.

Other media are also commonly used in NFT leafy crop production. Oasis cubes are composed of

plastic polymers, and are essentially foam blocks that retain high levels of both water and air while having

little impact on nutrients. Coconut coir and peat moss, media that are quite common in ornamental

greenhouse production, are also potentially valuable for hydroponic leafy crops. While they do provide

adequate moisture retention and aeration, they differ in some key areas from rockwool and Oasis. They do

have the ability to hold onto some nutrients (exchange capacity) and this can be an asset in buffering changes

in the nutrient solution. In small systems without a large volume of nutrient solution buffer, this resistance to

change in the media can provide a measure of protection to your young plants if your solution deviates from

ideal conditions.

2. The Nutrient Solution

A. Using Hydro-Gro Fertilizer to Prepare Nutrient Solutions

Hydro-Gro is a general purpose hydroponic soluble fertilizer that has been formulated for the needs of the

plant without taking into account your source water. If the source water has an electrical conductivity of less

than 0.3 mS/cm (300 µS/cm), Hydro-Gro can often be used satisfactorily for crop production. However, simply

evaluating your source water based on EC is an incomplete method because it only quantifies the total

conductivity of dissolved ions and does not describe which ions are contributing to that conductivity. It is

always best to have your source water analyzed for chemical composition. Do not use water that has been

treated by a water softener because the sodium and chloride levels will be higher than desired for plant

production.

The recipes that follow have been prepared as a guide for use of this premixed fertilizer. The Hydro-Gro dry

mix shipped to you can be used in one of two ways.

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Method 1) The Hydro-Gro and calcium nitrate can be used to prepare stock solutions, which can then be

diluted to produce the feed solution that is delivered to the plants. This can be a more efficient method of

making fertilizer as the concentrates will last for quite a while and will provide a consistent method of

adjusting and maintaining your nutrient solution.

Method 2) The Hydro-Gro, calcium nitrate, and potassium nitrate can be used as dry materials and added

directly to your source water to create a feed solution that is the strength to be delivered directly to your

plants.

Method 1: Preparing Hydro-Gro Stock Solutions from Dry Ingredients

Supplies needed:

- 1 lb of Hydro- Gro ( part #FER3021, FER3022)

- 1 lb of calcium nitrate (can be purchased from CropKing for proper purity)(FER3024, FER3025)

- Acid (pH down or dilute sulfuric acid)(HYD5000)

- Stock tank with a volume of 25-100 gallons

- Scale with 0.1 oz precision

- Concentrate jugs- 2 x 1 gallon jugs (recommended)

Preparing Concentrate Solutions

- Two 1 gallon jugs are used to prepare concentrate solutions consisting of Hydro-Gro (concentrate

A) and calcium nitrate (concentrate B) for a 1:100 dilution to reach feed strength (1 gallon of

concentrate solutions A and B will prepare 100 gallons of feed strength solution).

• Add 13 oz of Hydro-Gro to empty 1 gallon jug, label this jug concentrate A

• Fill jug to 1 gallon with warm water, mix until fertilizer is dissolved; it is best if the source water has

an electrical conductivity below 0.3 mS/cm. If the source water has a high EC, it can be more

difficult to provide all the needed nutrients to the plants.

• Add 10 oz of calcium nitrate to empty 1 gallon jug, label this jug concentrate B

• Fill jug to 1 gallon with water. Mix both solutions thoroughly making sure all fertilizer is dissolved.

Add enough acid to keep the pH of the concentrate between 5.5 and 6 pH. Now your two

concentrate solutions are prepared.

Concentrate A Concentrate B Target EC- mS/cm

Hydro-Grow Calcium Nitrate Warm/High Light Cool/ Low Light

Lettuce 13 oz 10 oz 1.4-1.7 1.8-2.1

Preparing Feed Solution from Concentrate Solutions

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• Begin with a 25-100 gallon feed tank, fill tank 75% full with water.

• Measure the EC of the clear water. Our target EC for lettuce is 1.4-2.1 mS/cm depending on the

growing environment (as discussed below).

• For a 25 gallon feed tank add one quart of concentrate A and one quart of concentrate B; for a

100 gallon feed tank add one gallon of A and one gallon of concentrate B. Remember to not let

the two concentrates mix with each other until they are diluted in water to prevent any

fertilizer salts from precipitating out of solution.

• Bring the EC up to the target range by adding additional small volumes of concentrate if needed

and measuring EC with your meter. When adjusting the nutrient solution, always add equal

quantities of Concentrate A and Concentrate B to increase the EC. Additional source water can

be added if the EC becomes higher than the target value.

Method 2: Preparing Hydro-Gro Feed Solutions from Dry Ingredients

Preparing Feed Solution from Dry Fertilizers

• Begin with a 25-100 gallon feed tank of known volume, fill tank 75% full with water.

• Measure the EC of the clear water. Our target EC for lettuce is 1.4-2.1 ms/cm depending on the

growing environment (as presented in the table above and discussed below).

• From the table below, add the appropriate quantity of Hydro-Gro, and Calcium Nitrate fertilizer

that corresponds with your tank volume. Mix each fertilizer well to assure that the fertilizer is

dissolved before adding the next fertilizer material. (1 ounce is approximately 2 tablespoons)

Feed Tank Solution

Volume (gallons) Hydro-Gro Calcium Nitrate

10 1.3 oz. 1.0 oz.

15 1.9 oz. 1.5 oz.

20 2.5 oz. 2.0 oz.

25 3.1 oz. 2.5 oz.

30 3.8 oz. 3.0 oz.

100 13 oz. 10 oz.

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B. Monitoring and Adjusting the Electrical Conductivity

The Bluelab Combo meter or the Myron EC meter is used to measure the electrical conductivity (EC) of the

fertilizer solution. Essentially, it gives us a value that corresponds to the total quantity of nutrients in solution.

We typically want to maintain the electrical conductivity in the 1.4 to 2.1 mS/cm range for lettuce and most

herbs as shown in the above table. The EC range is dependent on the time of year. Use the lower EC in the

summertime and the higher EC in the wintertime because warm summer temperatures and high light can

increase the demand for water in the plant. Reducing the concentration of fertilizer in solution by lowering the

EC will make it easier for the plant to take up water.

• If the electrical conductivity level is lower than desired, add small amounts of both Hydro-

Gro and calcium nitrate concentrates in equal amounts and mix well until the EC reading rises

to the desired level.

• If the electrical conductivity level is higher than desired, add source water until it is brought

down to the optimum range. (Remember to adjust the pH of the solution after new source

water is added as described below.)

• Check the electrical conductivity every day, and make any adjustments needed to keep the

solution in proper ranges.

C. Monitoring and Adjusting the pH of the Nutrient Solution

The pH of the nutrient solution being fed to the plants should be in the 5.5 to 6.0 range to keep the

nutrients from becoming unavailable. If the pH rises too high, nutrients can precipitate to form other salts and

this reduces the availability for plants. Low pH can physically damage roots, so it is important to not let the pH

drop below approximately 5.0. To maintain the optimum pH range, test the pH of your source water using the

Bluelab Combo meter or pH test kit. If using a combo meter, be sure the meter has been properly calibrated

by using the standard solutions that are provided.

• Most source water has a higher pH than desired which must be lowered using pH down solution also

provided with your growing kit. Be cautious when reducing the pH of your solution as reactions can

occur quickly. Remember that how quickly your water responds to pH management and how much pH

down it takes to lower the pH will depend on the composition of your source water.

• Also keep in mind that when plants take up nutrients from solution, pH changes can occur. So, monitor

your pH daily to keep the solution in the correct range to assure that nutrients are available for plant

uptake.

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D. Changing the Reservoir and Cleaning the System

• Once every week to two weeks, the contents of the reservoir should be discarded to prevent

imbalances in the ions in the nutrient solution. Plants do not use all nutrients at the same rate, so over

time, the solution will contain more and more of the nutrients plants take up in smaller quantities.

Additionally, other ions in your source water, such as sodium, will build up over time. The solution may

be used to water the grass or other plants in a soil media.

• Recharge the reservoir with a fresh mix of fertilizer solution using the nutrient mixing instructions

above.

• Clean the channels after harvesting one group of plants and before planting or transplanting new

plants into the system. It may also be necessary to clean your reservoir to prevent algae or other

materials from interfering with the system function or plant growth.

3. Seeding, Transplanting, and Growing the Crop

As a general timeline, leafy crop seedlings are transplanted into the channels about two weeks after seeding

and then harvested directly from the channels when mature- about 4 to 5 weeks after transplant. So, the

typical timing of production is 6 to 8 weeks for a lettuce crop.

A. Growing Transplants

• Soak or flush the rockwool or oasis cubes in pH corrected nutrient solution before they are seeded. The

suggested method is to place a pad of rockwool cubes in the black seedling tray (10” x 20”) with holes

or in a mesh tray. Place the slotted or mesh tray in a tray without holes and fill with pH corrected

water. Using this method the rockwool cubes will be totally saturated with water. Remove the tray

with holes and let the excess water drain for a few minutes. This method is used because it is best for

the cubes to be evenly moist to enable the most rapid germination. Additionally, rockwool is

manufactured using an industrial process, so flushing the cubes can remove any excess salts left over

from manufacturing. If using peat or coir based media, you need only be sure that the cubes are evenly

moist.

• Considering the small size of the growing system, you may be doing the seeding by hand. If using

pelleted seed, it will be easier to handle and plant individual seeds. Raw (or unpelleted) lettuce seed is

quite small and can be more challenging to plant by hand. One method that may save some time in

seeding is using an index card. First, fold a 3 x 5 card in the center. Then, place a small amount of seed

on the card and use a pencil or similar object push to one seed at a time into the dibble hole in the

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cube. We suggest that you seed an extra10-20% more seed than the number of plants you need for the

system. This allows the transplanting of only the strongest seedlings.

• Place the seeded pads into the nursery tray or a seedling tray with nutrient solution flowing through

the tray. Starting the plants in a nursery tray will allow you to start new plants while the maturing

plants are still in other channels in the system. This type of arrangement will allow you to continuously

produce leafy vegetables.

• The rockwool, Oasis or peat/coir growing media will maintain moisture needed for the seeds to begin

germination. If the conditions in your growing area lead to rapid drying of the tops of the cubes, you

can place a small sheet of cardboard or newspaper over the cubes for the first day or so. Do not use a

plastic dome or plastic sheet to cover the seeded cubes if there is any light source. Light can rapidly

heat up the cube which can prevent the seed from germinating or reduce the seedling quality. Lettuce

will germinate in 24 to 48 hours and you will be able to see the initial root and then shoot emerging.

Basil and most other herbs will take a few days to germinate.

B. Transplanting

Generally, seedlings are transplanted from the nursery into the grow-out NFT channels when they are

approximately two to three weeks old. Use only the seedlings that are the fastest growing and most vigorous.

The smaller plants will generally never catch up to the rest of the seedlings and your plants will be rather

unevenly sized when you harvest. The larger outside leaves should be approximately 2 to 2-1/2 inches long at

transplant, and there should be 5 to 7 leaves in various stages of expansion. Additionally, it is important that

there are roots emerging from the cube to begin to take up water and nutrients for the young plant after

transplanting.

• Plants in one channel are staggered with the adjacent channel to maximize space usage as the plants

grow toward maturity. To achieve this staggered planting, the top caps are punched so that the end

plant hole is closer to one end than to the other end.

• Start one channel with the hole close to the feed end of the channel and then start the next channel

with the top cap oriented so that the hole is farther away from the feed end of the channel to

accomplish the staggered pattern.

• Separate grow blocks containing the plants. Rockwool and oasis cubes should be pulled or broken

apart gently. Handle the transplants by the rooting material rather than by the leaves or stems of the

plant itself. Peat cubes may need to be gently popped out from the bottom of the tray rather than

pulled from the leaves.

• Turn the nutrient flow on to the plants as soon as the channel is in place in the system and the plants

are being or have been put into it.

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C. Growing Conditions

Temperature Minimums

For best growth, night temperatures should be at least 55°F and day temperatures should be at least 65 to

68°F. Lettuce can be grown at cooler temperatures, but the growth rate will be slowed and your total

production time will be increased.

Temperature Maximums

High temperatures can lead to bolting of the lettuce plants. The plant goes into the reproductive growth

phase. It then becomes bitter and is not edible. Most leafy greens, such as lettuce, kale, chard, etc. are cooler

season crops that grow best with temperatures below 80 to 85 °F.

Light

The young seedlings should receive a minimum of 150 µmoles/m2/s of light (800 foot candles) for 12 to 16

hours per day. Less than this amount for any significant (longer than nighttime darkness) can bring about

excessive elongation of the leaves and stem of the young plants and reduce the quality of your plants.

Artificial Light

For the seedlings when they are on the close spacing before being transplanted, the use of artificial light may

be of benefit during the winter months. When artificial lighting is used, set the time clock for 16 hours on and

8 hours off per day. For small systems, T5 florescent lights can be a cost efficient means of increasing light in

the growing area.

D. Harvesting

• Remove the feed line from the channel and place it into the adjacent channel or pinch it closed with a

clip.

• Slide the channel out of the growing system as you harvest so that you can reach all of the plants in the

channel. Some growers do prefer to remove the entire channel and take to a packing table where it

can be harvested, cleaned, and replanted.

• Firmly grasp the base of the lettuce and the cube just above the top of the channel. Pull the plant

straight up to free the roots from the cover.

• Once the lettuce head is out of the channel, turn the head upside down and trim off the excess roots

with clippers or break them off with your hand. At this point, also completely removal any pale,

discolored, and dried older leaves at the base of the plant. Place the excess roots and removed plant

material into a garbage container.