Related guides: Hydroponics for Beginners · Kratky
A hydroponic system is ready for plants only after water, roots, light, support, plumbing, and safety have all been tested together. This checklist is designed for a small home system, whether it is a passive reservoir, DWC bucket, drip setup, NFT channel, ebb-and-flow bed, or tower.
1. Confirm the crop and its mature size
Write down the crop before buying equipment. Note its mature height, root volume, water use, light needs, harvest timing, support requirements, and whether it needs pollination. Lettuce and basil can fit a compact setup; a tomato or cucumber can turn the same setup into an unstable, thirsty system.
Do not size the system for the seedling. Check whether the lid, net pot, reservoir, trellis, light, and floor area can support the mature plant. If several crops share a reservoir, choose plants with reasonably similar growth rates and nutrient preferences.
2. Choose a safe location
- Use a level surface that can carry the reservoir at full working weight.
- Keep the system away from heat sources, direct sun on the reservoir, and furniture that cannot tolerate a spill.
- Leave enough room to remove the lid, inspect roots, drain the reservoir, and reach every fitting.
- Place electrical connections above possible splash height and create drip loops in cords.
- Keep children, pets, and fertilizer concentrates away from the working area.
One liter of water weighs about one kilogram, so a full tote can become heavy quickly. Test the location with the empty system first, then consider the full weight of water, media, equipment, and mature plants.
3. Check the reservoir and container
Use a clean, suitable container that blocks light from nutrient solution. Light leaks encourage algae and can warm the water. Confirm that the reservoir has enough working volume for the crop and the time between checks. Mark the normal fill level and the minimum level where the pump, air stone, roots, or return line still function correctly.
Inspect lids, gaskets, bulkheads, drain fittings, and seams. A reservoir that looks watertight when empty may leak once the water pushes against a fitting. Never rely on a towel under the system as the leak plan; repair the cause and retest.
4. Install the root support
Set the net pot, raft, grow tray, or planting site so the plant is stable without compressing the stem. The medium should hold the plant upright while allowing water and air to reach roots. Do not bury the stem base or keep the crown constantly wet.
For a passive Kratky system, the initial water level should reach only the lower roots or lower medium. As roots develop, a falling level creates an air gap. For DWC, roots can extend into the aerated solution, but the entire net pot should not remain saturated. For channels and drip systems, verify that the root zone drains instead of staying flooded.
5. Test pumps, air, drains, and timers
Run the system with plain water before adding fertilizer. Confirm that the air pump produces steady bubbles, the circulation pump moves water at the intended rate, the timer switches reliably, and every drain returns water without overflowing. Watch at least one complete flood-and-drain cycle for an ebb-and-flow system.
- Route tubing so it cannot kink when the lid or tray is replaced.
- Use a check valve where backward flow could flood an air pump.
- Protect pump intakes from roots and loose media.
- Keep return lines above the reservoir’s water level when the design requires air separation.
- Measure the time needed to empty and refill each section.
Mark normal water levels and listen to the system. A pump that is quiet during a five-minute test may become noisy when the reservoir falls. Test the lowest expected water level, not only the first full fill.
6. Prepare the water and nutrients
Measure the actual working water volume. Record the water source, temperature, fertilizer product, and date. Add nutrients according to the label, diluting separate parts as directed. Never combine concentrated fertilizer parts directly together.
If you use EC, calibrate the meter and write down the reading with units. PPM is a conversion convention rather than one universal scale, so record the meter’s scale. The EC to PPM calculator and PPM to EC calculator can convert readings but cannot select the right dose for a crop.
Test pH after nutrients are mixed. Make small adjustments with a suitable product and allow the solution to mix before retesting. If pH changes rapidly, investigate water alkalinity, nutrient strength, plant uptake, evaporation, and root health rather than repeatedly correcting the same symptom.
For the next step, see the DWC.
7. Verify the light
Place the fixture at the planned canopy height and check coverage across the whole planting area. Wattage alone does not describe usable plant light. Look for stretched stems, pale growth, leaf bleaching, heat stress, and strong differences between edge and center plants.
Set a consistent schedule before planting. If you have a PPFD reading, the DLI calculator can estimate daily light from intensity and hours. Treat the estimate as a planning aid and adjust based on the actual crop and canopy.
8. Test the system without plants
Let plain water run through every part of the system. Check for leaks while the pump is on and after it stops. Confirm that the reservoir does not siphon unexpectedly, the drain does not clog, and the lowest planting site still receives the intended water.
For a tower, check that each site receives enough flow and that the tower remains stable when filled. For NFT, check the channel slope and the return path. For drip, confirm that each emitter delivers water and that the media drains. For DWC, confirm aeration throughout the reservoir and that the air stone is not trapped under roots or equipment.
9. Add healthy plants
Use healthy seedlings or seeds started in a clean, appropriate medium. Remove loose garden soil before placing a plant into a hydroponic root zone. Transplant gently so the roots are not crushed, and give the plant the light and water access needed for recovery.
Start with fewer plants than the maximum number of sites. Empty sites make it easier to observe flow, and fewer plants reduce the risk of a small problem spreading before you understand the system.
10. Establish a maintenance routine
Daily or near-daily
- Check leaves for wilting, heat stress, pests, and sudden changes.
- Check water level, pump or air-pump operation, leaks, and unusual noise.
- Confirm the light schedule and plant support.
Weekly
- Measure pH and EC when possible and record the time and water temperature.
- Inspect roots through an access point and look for soft tissue, odor, or debris.
- Clean spills, remove dead leaves, and inspect tubing, fittings, and air stones.
- Compare plant growth with the previous record rather than reacting to one leaf.
Between crops
- Drain and discard old solution.
- Remove roots and plant debris.
- Clean and sanitize reusable parts according to their material and product label.
- Rinse, inspect, and run a plain-water test before planting again.
11. Create a failure plan
Decide what happens if the pump stops, power fails, a reservoir leaks, or the room overheats. Keep a spare airline, check valve, fuse or suitable replacement part, clean container, and enough water to protect the crop while you repair the system. A backup air pump may be more useful than an extra nutrient additive.
Write the normal water level, pump schedule, nutrient recipe, and emergency contact or action beside the system. Someone helping you should be able to tell whether the water is too low or the pump has stopped without guessing.
Final pre-plant checklist
- Crop and mature size match the container, light, and support.
- Reservoir is stable, opaque, clean, and large enough for the expected water use.
- Net pot, medium, lid, raft, or tray supports the plant without burying the crown.
- Pump, air stone, drains, tubing, and timers have passed a plain-water test.
- Water volume, fertilizer, pH, EC or PPM scale, and light schedule are recorded.
- Electrical connections are protected from splashes and power can be disconnected safely.
- A daily check and a pump-failure plan are written down.
Related guides
Start with Hydroponics for Beginners for the overall routine, then compare Kratky and DWC before choosing the equipment. The hydroponics definition guide explains how the main system types deliver water, nutrients, oxygen, and support.
