- Read crop-stage targets in elemental mg/L.
- Plan support, irrigation and harvest access.
- Account for coupled nutrient contributions.
01 / The crop changes the infrastructure
Tomatoes, peppers and cucumbers need more than a larger dose of lettuce fertilizer. Root volume, canopy support, pruning, pollination and access for harvest shape the installation. Select a cultivar intended for the growing environment and its available season.
Use a trellis anchored independently of light irrigation lines. Plan a safe working height and a route for removing the mature crop. Buckets or media slabs can provide serviceable root volume, while each container still needs reliable drainage and uniform delivery.
Reading: Hydro hints: Buckets ↗
02 / A published elemental ppm example
UF/IFAS HS796 provides these final delivered nutrient targets for greenhouse tomatoes in Florida. They are elemental mg/L, approximately ppm, and include the contribution of source water. They are a context-specific reference rather than a universal recipe for every climate, tomato system or other fruiting crop. The publication gives final solution pH 5.8–6.2.
The changing N and K values demonstrate why a single fixed product ratio may not exactly match all growth stages. Calcium nitrate contributes both calcium and nitrogen; increasing it to fix one element also changes the other. Account for all products and water contributions before reformulating.
| Stage | N | P | K | Ca | Mg | S |
|---|---|---|---|---|---|---|
| Transplant → first cluster | 70 | 50 | 120 | 150 | 40 | 50 |
| First → second cluster | 80 | 50 | 120 | 150 | 40 | 50 |
| Second → third cluster | 100 | 50 | 150 | 150 | 40 | 50 |
| Third → fifth cluster | 120 | 50 | 150 | 150 | 50 | 60 |
| Fifth cluster → termination | 150 | 50 | 200 | 150 | 50 | 60 |
Reading: Nutrient Solution Formulation for Hydroponic Tomatoes in Florida (HS796) ↗
03 / Establish the supported crop
Pre-wet the receiving medium and verify every emitter before transplant. Install the initial support early so it does not damage an established root system later. Label plant, cultivar, transplant date and nutrient stage.
Choose the pruning and training method recommended for the cultivar. Removing shoots indiscriminately can reduce useful canopy or fruiting sites. Keep tools clean between plants and inspect wounds during routine crop walks.
- Confirm root volume, drainage and mature canopy access in the design.
- Transplant healthy starts into uniformly wetted medium and verify emitter placement.
- Support the stem with a method that accommodates growth without constriction.
- Observe flowering and fruit set; use crop-appropriate pollination guidance for the protected environment.
- Record fruit load and stage before changing the nutrient program.
Reading: Hydro hints: Buckets ↗
04 / Link fruit quality to the whole system
Use supply and drainage observations to tune irrigation as leaf area and weather change. A timer that served a small transplant may under-deliver to a fruiting canopy. Verify the farthest emitters again as filters load.
Fruit disorders can reflect water stress, temperature, pollination and nutrient interactions. Blossom-end rot is associated with calcium delivery to developing fruit; adding calcium without checking water and root conditions can miss the problem. The Florida guidance also discusses excess potassium interfering with calcium and magnesium uptake.
Reading: Nutrient Solution Formulation for Hydroponic Tomatoes in Florida (HS796) ↗ · Irrigation in Hydroponic Systems ↗
05 / Close the crop cycle
Record usable fruit mass, unmarketable fruit, labor, support changes and nutrient batches by stage. Keep cultivar trials distinct. At crop removal, inspect drainage and retained roots, then clean and re-test the system before installing the next crop.
Compare a new nutrient program against a well-recorded baseline. Change one major variable at a time so the next crop teaches something usable.
FIELD QUESTIONWhy can calcium nitrate alone fail to match a low-N, high-Ca target?
It adds both N and Ca in a fixed ratio. Enough product to supply all calcium may exceed the nitrogen target, particularly if other fertilizers also supply N.
Parts & buying criteria
Showing drip / dutch buckets. Quantities describe the teaching model. Specify real working volume, support, fittings and instruments for your installation.
01Nutrient reservoir1 · illustrated quantity+
Stores the measured nutrient solution beneath or beside the growing area.
Inspect: Compare the surface with the pump intake or lower roots; freeboard is deliberate.
Maintain: Record level before refilling, keep light out and verify temperature, EC and pH.
Opaque, cleanable, intended-use container with volume marks and service access.
Supplier links can be added by the publisher. The criteria stand independently.02Pump & supply1 · illustrated quantity+
Moves nutrient solution from the reservoir to the growing area.
Inspect: Trace installed lift and branching; the pump label does not prove delivered flow.
Maintain: Measure output after service and inspect intake, filter and minimum water level.
Pump curve matched to installed head, required pressure and service needs.
Supplier links can be added by the publisher. The criteria stand independently.03Dutch buckets3 illustrated · illustrated quantity+
Contain a large root-zone medium with a defined drainage outlet.
Inspect: Inspect the flood level, pot bases and accessible drain position.
Maintain: Verify full drainage and inspect moisture in representative pots.
Rigid cleanable tray with independent overflow and adequate support.
Supplier links can be added by the publisher. The criteria stand independently.04Root-zone mediumFor illustrated containers · illustrated quantity+
Stores moisture and air around the roots in the illustrated containers.
Inspect: Compare the medium surface with irrigation and drainage.
Maintain: Inspect wetting at several depths; prevent fines from reaching drains and emitters.
Prepared, stable grade matched to the irrigation method and crop.
Supplier links can be added by the publisher. The criteria stand independently.05Drip emitters3 illustrated · illustrated quantity+
Distribute solution separately to each container.
Inspect: Trace the manifold and the small outlet above each plant position.
Maintain: Collect equal-time samples and compare output; flush the main line before installing emitters.
Emitter pressure requirements matched to pump and filter; flushable connections.
Supplier links can be added by the publisher. The criteria stand independently.06Drain & overflow1 · illustrated quantity+
Returns drainage to the reservoir and provides a controlled high-water route.
Inspect: Follow the full slope and look for the separate high-level opening.
Maintain: Test pump-off drain-back and keep roots and medium out of the outlet.
Accessible fittings and verified capacity under normal and fault conditions.
Supplier links can be added by the publisher. The criteria stand independently.Evidence beside the lesson.
Source checks: September 2026. The geometry, inspection exercises and worksheets are original teaching material. The named organizations have not endorsed or reviewed this site.
Published recipe rates and planning ranges retain their source context. Calculator equations are accounting tools; they do not predict uptake, yield, toxicity or safe stocking. Model dimensions, water speeds, roots and fish counts are illustrative. Verify species, crop, source water and product labels for a real system.
- Oregon State University ExtensionHydro hints: Buckets ↗
Bucket crop support, delivery, media and drainage.
- University of Florida IFAS ExtensionNutrient Solution Formulation for Hydroponic Tomatoes in Florida (HS796) ↗
Elemental ppm by fruit-cluster stage in Florida greenhouse tomato production.
- University of Kentucky Center for Crop DiversificationIrrigation in Hydroponic Systems ↗
Media irrigation and delivery management.
The next useful connections.
Drip and Dutch buckets: deliver to every plant
Design a serviceable bucket system for larger crops, then measure irrigation uniformity and drainage.
Interactive tool · 6 min + guided practice →Nutrients & mixingNutrient mixing: from grams to elemental ppm
Scale two documented fertilizer examples, read the bag analysis and calculate what actually enters the final solution.
Interactive tool · 6 min + guided practice →