How to set up SNAP hydroponics.

By PJA Santos and ETM Ocampo

A. Establish the Seedlings

Materials needed:

a. Sowing tray – shallow box/basin with drainage holes at the bottom

b. Growing media – aged coconut coir dust or charcoaled rice hull or a mixture of both; saw dust (old stock/unused); fine sand (may be combined with coir dust and or charcoaled rice hull)

c. Seeds bought from your local agricultural store

d. Watering solution (water with SNAP nutrient solution available at the IPB)

Procedure:

1. Fill the sowing tray with a 1-inch thick layer of the growing media.

2. Level the media.

3. Scatter the small seeds uniformly and thinly on the growing media (the amount will depend on your need).

4. Water liberally as needed and expect the seeds to germinate in 3-5 days.

5. Grow the seedlings for 10-15 days.

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Sowing tray made from recycled styrofoam packing materials.

B. Prepare the Seedling Plugs

Materials needed:

a. Styrofoam cups (8 oz.)

b. Cutter or knife or hacksaw blade

c. Growing media

d. Seedlings (10-15 days old)

e. BBQ sticks or the like

Procedure:

1. Prepare the styrofoam cups by using a knife or cutter to cut 4-5 equally spaced slits, with each one running halfway from the side to the bottom of the cup.

2. Fill the seedling plugs with the growing media (1-inch thick).

3. Make a hole in the middle of the growing media in the cup. Transplant the seedlings from the sowing tray using a stick to gently uproot the seedlings from the sowing tray. Transfer only one seedling per cup. Make the transferred seedling stand firmly by lightly pressing the media around its base.

4. Water the seedling plugs carefully and gently.

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The seedling plugs.

C. Prepare the Growing Boxes

Materials needed:

a. Styrofoam boxes (preferably boxes used to pack imported grapes or other fruits)

b. Big milk tin can (370-ml size) with one lid cut open and sharp enough to bore a hole through the styrofoam

c. Polyethylene plastic bag (20”x 30”, 0.003 inch thick)

Procedure:

1. Make 8 holes (for a typical styrobox of imported grapes) on the lid/cover of the box using the tin can as a hole puncher.

2. Use the plastic bag to line the bottom half of the box. The plastic lining will enable the SNAP hydroponics system to contain the liquid nutrient solution.

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Growing boxes using packaging materials of imported grapes and other fruits.

D. Running the SNAP Hydroponics System

Materials needed:

1. Seedling plugs

2. SNAP nutrient solution

3. Growing boxes with 10 liters of water each

4. Benches or stand (optional) – where the growing boxes will be placed under a shelter

5. Rain shelter (optional during dry season or roof awning facing east for the earliest and longest sunlight possible)

Procedure:

1. For the plants to grow well, locate the SNAP hydroponics system where it will best receive the morning sunlight—the earlier, the better. It should be under a roof awning, if not a transparent shed, to prevent rain water from getting into the system.

2. Arrange the growing boxes on the bench (optional) with covers removed.

3. Fill each growing box with about 10 liters of tap water.

4. Add 25 ml SNAP A nutrient solution to each box and stir well.

5. Add an equal amount of SNAP B to each box then stir well again.

6. Put back the cover of the box.

7. Place the seedling plugs into the holes of the cover. See to it that the holes of all cups are ‘plugged’ evenly.

8. Ensure that the bottom of the cups are submerged in the nutrient solution ½ inch deep, not any deeper or shallower. If not, add more water until the desired depth is reached.

9. Examine the boxes for leaks and do some troubleshooting as needed.

10. Visit the setup every morning, as early as you can, to catch any insect larva that may eat the plants (the larva is visible early in the morning, after which they tend to hide from the sun, making it harder to find them).

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The SNAP hydroponics system, being used to grow leafy lettuce here, is placed under an awning at the IPB.

Expect the nutrient solution level to recede faster when the plants are much bigger than when they were still seedlings.

No replenishment is needed when growing lettuce, pechay, mustard, or similar vegetables that are grown for a month or less, but replenishment is needed for vegetables that are grown for more than a month, such as tomato or sweet or hot pepper.

However, when replenishing, never allow the level of the solution to submerge the whole root system; at most, submerge only the lower half of the root system or even less.

Note: It is more practical to prepare the nutrient solution in a drum, distribute the prepared solution to each growing box, and use the leftover solution for replenishments when the level in the hydroponics boxes has gone down.

For more information, please contact: Physiology Section, Institute of Plant Breeding, UP Los Baños, (049) 576-3189 or The Director’s Office, Institute of Plant Breeding, UP Los Baños, (049) 536-5287, or email pjasantos@yahoo.com or eteresaocampo@yahoo.com.

This appeared as part of “Hydroponics in a SNAP” in Agriculture Monthly’s May 2015 issue.