- Put a kit and a self-built unit on the same checklist of what a home system needs.
- Turn a kit’s rated wattage into a yearly energy figure at your own tariff.
- Weigh proprietary pods, app reminders and maker’s spares against open consumables and generic parts.
01 / One checklist for both
Boxed or built, a home unit must supply what University of Minnesota Extension lists: plants, a container, water, a way to anchor the plants, nutrients and a light source. UMN calls deep water culture the simplest home category, builds it from a 5-gallon bucket or storage bin with a drilled lid, and says of kits that you can buy premade systems, “but it is more affordable and nearly as easy to build your own”.
UF/IFAS HS1422 files the same choice under budget: prefabricated systems are available, or systems can be built at home. HS1488’s Kratky bucket is the no-electricity end of building: bucket, lid, hole saw, net cups, grow cubes, nutrients and pH strips, with an EC/TDS meter optional. A kit fuses container, support, light and timer into one housing, and they are chosen for you as a set.
Reading: Small-scale hydroponics ↗ · Growing Lettuce in Small Hydroponic Systems (HS1422) ↗ · “Set It and Forget It” Hydroponic Lettuce (HS1488) ↗
02 / Plant sites, root space and the light above them
A kit’s plant count is fixed by its housing. Three manufacturer pages read on 17 September 2026 show the spread: the AeroGarden Harvest lists 6 pods, a 20 W LED grow light and an adjustable grow height up to 12 inches; the Click & Grow Smart Garden 9 lists 9 pods, 13 W power consumption and a 4 l water tank; the Personal Rise Garden lists 12 plants, 30 W of LED lighting and an 18-inch overall height, with no grow height stated. Makers’ own figures, quoted for range, not rank. Grow height is canopy clearance; the tank is the water every pod shares.
A bucket inverts this. HS1488 allows 1–1.5 gallons of water per lettuce plant, so three heads per 5-gallon bucket, and UMN’s example is one or two buckets under a single 9-watt LED grow light with a PPF of 16 micromoles per second. Fewer plants, but gallons of root space each and a lamp you can raise.
Reading: AeroGarden Harvest (product page, SKU 901100-1200) ↗ · The Smart Garden 9 (product page, model Smart Garden 9) ↗ · Personal Rise Garden (product page) ↗ · “Set It and Forget It” Hydroponic Lettuce (HS1488) ↗ · Small-scale hydroponics ↗
03 / What the rated wattage costs to run
Rated wattage is the one box number you can turn into a running cost before buying: kWh = watts × hours per day × days ÷ 1,000, then your own tariff. UMN works its own example: a 9-watt light for 14 hours a day, every day, is about 45,990 watt-hours a year (UMN prints the unit as watts), and at 12 cents per kilowatt-hour, which it calls a common price in 2020, about 45 cents a month or $5.44 a year. A dated figure, not a quote.
At 16 hours a day for 30 days, 13 W gives 6.24 kWh, matching Click & Grow’s published 6.2 kWh per month; 20 W gives 9.6 kWh; 30 W gives 14.4 kWh. The light is a small monthly line either way. A build lets you swap the fixture; a kit fixes it.
Reading: Small-scale hydroponics ↗ · The Smart Garden 9 (product page, model Smart Garden 9) ↗
04 / Pods, apps and spare parts
Kits run on the maker’s consumables. Click & Grow describes patented, pre-seeded Plant Pods; the Harvest ships with a 6-pod seed pod kit and a 3 fl oz bottle of liquid plant food; the Rise garden ships a seed starter set and a nutrient starter set. A bucket runs on UMN’s open list: any clean food-safe container, soaked starter cubes and any pre-made hydroponic fertilizer at label rate whenever water goes in.
Sensors are mostly reminders. The Rise page lists Wi-Fi, an app and notifications for water, nutrients and harvest, and gives nutrient delivery as “manual”, the app saying when and how much to add; the AeroGarden page lists water and plant food reminders. Neither lists an EC or pH reading, so the app is a calendar, not a meter. HS1422 says gardeners should consider a conductivity/pH meter and a dissolved-oxygen meter; either reads a kit’s tank as readily as a bucket.
Click & Grow’s page says wear parts are replaceable, links a spare-parts section and states that the grow light, the only component it lists as limited-life, lasts a minimum of 7 years; other makers vary, and a discontinued model can strand its pods. A built DWC unit is a bucket, lid, air pump, tubing, diffuser and lamp, each sold anywhere.
| Criterion | Countertop kit | Self-built DWC or Kratky |
|---|---|---|
| Plant sites | Fixed: 6, 9 and 12 on the pages cited. | Drilled to suit; HS1488 fits three lettuce per bucket. |
| Root space | One shared tank (4 l, Smart Garden 9). | 1–1.5 gal per plant (HS1488). |
| Light | Included, 13–30 W cited; canopy height fixed by the housing or arm. | Chosen, swappable; UMN’s 9 W example. |
| Consumables | Maker’s pods and plant food. | Any food-safe container, cubes, fertilizer (UMN). |
| Monitoring | App reminders; no EC or pH reading listed. | Handheld meter or strips (HS1422, HS1488). |
| Repairs | Maker’s spares, where offered. | Generic parts, any supplier. |
Reading: The Smart Garden 9 (product page, model Smart Garden 9) ↗ · AeroGarden Harvest (product page, SKU 901100-1200) ↗ · Personal Rise Garden (product page) ↗ · Small-scale hydroponics ↗ · Growing Lettuce in Small Hydroponic Systems (HS1422) ↗
05 / Cleaning, noise and what you learn
Cleaning is the same job: UMN’s drain, scrub, rinse and sanitize routine (1 tablespoon of household bleach per gallon, about 150–200 ppm, left to air dry) applies to a kit’s tank as much as a bucket. A kit’s tank and cups are small and, on Click & Grow’s description, dishwasher-safe; keep any lamp or electronics out of the dishwasher unless the maker says otherwise. A bucket takes more scrubbing but keeps electronics away from the water.
Noise follows the pump: Click & Grow calls its passive-watering gardens silent, a Kratky bucket runs nothing, and an aerated DWC bucket or a pumped kit hums all day. HS1488 notes that indoor growing under lights “increases costs and adds complexity to troubleshooting”; a kit hides that complexity. Building means you set the level, choose the fertilizer, read the EC and see the roots.
Reading: Small-scale hydroponics ↗ · The Smart Garden 9 (product page, model Smart Garden 9) ↗ · “Set It and Forget It” Hydroponic Lettuce (HS1488) ↗
06 / Total cost of ownership, then decide
Frame cost as categories; prices move and this site quotes none beyond UMN’s dated example. Capital: the kit, or bucket, lid, pump, lamp and meter. Light energy: watts × hours × days at your tariff. Consumables: pods and plant food, or seed, cubes and a fertilizer bag. Replacement: a maker’s spare or a new unit, against a generic pump or lamp. The kit wins on setup minutes and shelf space; the build on root space, repairs and what you end up knowing.
- Count the plants you eat weekly and the tallest one’s height; compare with pod count and grow height, or with HS1488’s 1–1.5 gallons per lettuce.
- Run kWh = W × hours × days ÷ 1,000 on the rated wattage for a year at your tariff.
- Price a year of pods or plant food against a bag of fertilizer and a sheet of cubes; record both as the consumables line.
- Look for a spare-parts page and a stated lamp life; for a build, note where each part is sold. Decide who measures: reminders, or the meters HS1422 names.
- Run one lettuce crop and record usable heads, kWh and minutes before judging the next unit.
FIELD QUESTIONA kit lists a 20 W light. You will run it 16 hours a day at 0.20 currency units per kWh. What does the light cost per 30-day month and per year, and how does the year compare with UMN’s 9-watt example?
20 × 16 × 30 ÷ 1,000 = 9.6 kWh, so 9.6 × 0.20 = 1.92 units a month. Per year, 20 × 16 × 365 ÷ 1,000 = 116.8 kWh, or 23.36 units. UMN’s example is 45,990 Wh ≈ 46 kWh, so this light uses about 2.5 times that energy; wattage and schedule set it, not whether the unit was bought or built.
Reading: “Set It and Forget It” Hydroponic Lettuce (HS1488) ↗ · Growing Lettuce in Small Hydroponic Systems (HS1422) ↗
Parts & buying criteria
Build your own parts & cost worksheet →
Showing aerated deep water culture. 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 diffuser and the lower roots; freeboard is deliberate. There is no pump intake in this single-vessel example.
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.
Check size, materials and operating conditions with your chosen supplier before ordering.02Lid & root support1 · illustrated quantity+
Holds the plant above the chamber or reservoir without pinching its crown.
Inspect: Separate the cover and inspect the basket or collar opening.
Maintain: Check fit as plants grow and keep unused openings covered.
Rigid compatible support with removable, correctly fitted baskets or collars.
Check size, materials and operating conditions with your chosen supplier before ordering.03Air pump & diffuser1 · illustrated quantity+
Delivers air below the water surface in this aerated DWC example.
Inspect: Trace the thin line from the dry pump to the diffuser. Bubbles are illustrative.
Maintain: Check actual delivery and dissolved oxygen; preserve backup air and prevent back-siphoning.
Rated output at the installed depth and diffuser resistance; accessible replaceable parts. Power it through ground-fault protection (GFCI/RCD) and keep the pump and its plug above the water line.
Check size, materials and operating conditions with your chosen supplier before ordering.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.
- University of Minnesota ExtensionSmall-scale hydroponics ↗
Root support, transplanting, light, aeration and cleaning.
- University of Florida IFAS ExtensionGrowing Lettuce in Small Hydroponic Systems (HS1422) ↗
Lettuce system choice and management.
- University of Florida IFAS Extension“Set It and Forget It” Hydroponic Lettuce (HS1488) ↗
A small non-circulating lettuce example; seasonal and product assumptions apply.
- Scotts Miracle-Gro · manufacturerAeroGarden Harvest (product page, SKU 901100-1200) ↗
Manufacturer specification accessed 17 September 2026: plant capacity 6 pods, 20 W LED grow light, adjustable grow height up to 12 inches, water and plant food reminders, and an included 6-pod seed pod kit and 3 fl oz bottle of liquid plant food; a product example, not an endorsement.
- Click & Grow · manufacturerThe Smart Garden 9 (product page, model Smart Garden 9) ↗
Manufacturer specification accessed 17 September 2026: plant pod capacity 9, power consumption 13 W and 6.2 kWh per month, 4 l water tank, patented pre-seeded Plant Pods, passive watering described as silent, wear parts replaceable with a garden spare-parts section, a grow light stated to last a minimum of 7 years, and dishwasher-safe cleaning; a product example, not an endorsement.
- Rise Gardens · manufacturerPersonal Rise Garden (product page) ↗
Manufacturer specification accessed 17 September 2026: growing capacity 12 plants, 30 W LED lighting, 18-inch overall height with no grow height stated, 2.4 GHz Wi-Fi with an iOS and Android app and notifications for water, nutrients and harvest, nutrient delivery listed as manual with the app indicating when and how much to add, and a seed starter set and nutrient starter set in the box; a product example, not an endorsement.
The next useful connections.
Deep water culture: build an aerated root bath
A complete single-vessel DWC workflow, from water level and air delivery to nutrient management and harvest.
6 min + guided practice →Growing methodsKratky: manage the water and the air gap
Grow a short-cycle crop without circulation, with enough starting solution and a fixed support that preserves the developing air zone.
6 min + guided practice →Crops & environmentLeafy greens and herbs: plan a repeatable crop
Choose a first crop, manage spacing and harvest timing, and avoid forcing every herb into lettuce conditions.
6 min + guided practice →Crops & environmentLight, temperature and humidity
Measure the growing environment at the canopy and root zone, then adjust one limiting condition at a time.
Interactive tool · 6 min + guided practice →ComparisonsKratky vs DWC for lettuce: pick by power, season and scale
Both methods hang lettuce roots in stored nutrient solution; they differ in where oxygen comes from, how much water each plant needs on day one and what fails first.
7 min + guided practice →