Hydroponics

Soilless growing for food crops. EC, nutrients, lighting, the works.

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Hydroponic systems work on a single principle: roots get water + nutrients + oxygen, and you control all three. Compared to soil growing, you trade compost and intuition for measurement and dosing. The tools here help with the measurement part.

1. Pick what you want to grow

Crop choice constrains everything else. Lettuce wants EC 1.0-1.4 and 22°C; tomatoes want EC 2.5-3.0 and 24°C. They don't share a reservoir well. The edible plant catalog has 231 crops with growing-system compatibility, EC ranges, light needs, and notable cultivar guidance for many species. Filter by your climate zone if you're growing outdoors or in a greenhouse.

2. Pick a system that fits the crops

The garden planner asks for your roster and growing system (DWC, NFT, vertical tower, drip, media bed, wicking, soil bed) and tells you whether the combination works. The 13 compatibility rules catch the classic mistakes: tomatoes in NFT channels won't work, lettuce and tomatoes can't share a reservoir at the same EC, deep-rooted crops in vertical towers will clog.

3. Get a combined feed recommendation

Once your roster is validated, the planner produces a target EC, target pH, NPK ratio, and per-crop deltas showing the tradeoff. Two approaches available: a balanced overlap target (default) or a dominant-feeder target (commercial mixed-bed standard). Per-crop growth stage matters; the planner lets you set each crop's stage independently for honest mixed-stage math.

4. Mix nutrients

The nutrient mix calculator gives you exact grams of Masterblend, GH Flora, or generic NPK blend per liter of reservoir at your target EC. The EC ↔ PPM converter handles the 500/640/700 PPM scale confusion that cheap TDS meters create.

5. Light the plants right

Indoor and greenhouse hydroponics live or die on the grow light calculator check. Each crop has a DLI target; the calc tells you whether your fixture × hours × PPFD achieves it. Lettuce at DLI 12 is fine; tomatoes need DLI 25+ to fruit. Mismatched lighting is the most common reason indoor hydroponic systems underperform.

6. VPD if you're going for yield

Vapor pressure deficit is the temperature-and-humidity sweet spot that maximizes transpiration without stressing plants. Hobby growers can skip this; serious indoor growers can't.

7. Cost reality check

The running cost calculator gives you a monthly electricity estimate for the pump, lights, and any heating/cooling. Indoor hydroponics under lights costs $50-200/month at typical electricity rates; greenhouse setups are far cheaper. Worth knowing before you scale up.

Tools

Reference

Articles

Hydroponics 4 min read

Cleaning and sterilizing between crop cycles

Pathogen carryover between crops is the silent yield killer. How to sanitize reservoirs, channels, and tubing with bleach, peroxide, or isopropyl alcohol.

Hydroponics 5 min read

Cloning plants for hydroponics

Take a cutting, root it, and transplant into your system. The technique works for basil, tomatoes, peppers, mint, and most herbs. 7-14 days to roots.

Hydroponics 5 min read

The real electricity cost of indoor growing

Lighting is 70-85% of your power bill. A countertop herb setup runs about $8/month. A serious grow tent costs $30-80/month. The math by system size.

Hydroponics 5 min read

Grow light height and coverage

The inverse square law means doubling the distance quarters the intensity. How to find the right height for your light and what PPFD maps actually show you.

Hydroponics 5 min read

Herbs that grow faster in hydro than soil

Basil, mint, cilantro, and chives grow 25-40% faster hydroponically than in soil. Actual yield comparisons and the lowest-effort systems that work.

Hydroponics 5 min read

Is hydroponic food as nutritious as soil-grown?

The research mostly says yes. Mineral content depends on what you feed the plant, not where its roots are. What the studies actually measured and what they missed.

Hydroponics 7 min read

Growing hydroponic tomatoes indoors

Indoor hydro tomatoes need pollination, pruning, EC management by growth stage, and serious light. How to grow them from seed to ripe fruit.

Hydroponics 5 min read

Microgreens: the fastest crop

Seed to harvest in 7-14 days, no nutrient solution needed, and high margins if you sell them. Seed density, growing media, and the basics of production.

Hydroponics 7 min read

Mixing hydroponic nutrients from dry salts

Dry salts cost a fraction of premixed liquid nutrients and last for years on a shelf. The mixing order matters, and getting it wrong locks out calcium.

Hydroponics 6 min read

Reading nutrient deficiency from the leaves

Mobile nutrients show problems on old leaves first. Immobile nutrients hit new growth. Here's how to tell nitrogen, iron, calcium, potassium, and magnesium apart.

Hydroponics 6 min read

Pest control for indoor grows

Fungus gnats, aphids, spider mites, and thrips are the four pests you'll actually encounter indoors. How to identify, prevent, and treat each without pesticides.

Hydroponics 6 min read

Why pH drifts in hydro and how to stabilize it

pH drift in hydroponic reservoirs is caused by nutrient uptake, not bad water. Plants release ions as they feed, and the direction of the drift tells you what they're consuming.

Hydroponics 7 min read

Root rot: identification, causes, and treatment

Pythium thrives in warm, low-oxygen nutrient solution. Keep reservoir temperature under 22 C, maintain 8+ ppm dissolved oxygen, and here's what to do if you're already infected.

Hydroponics 5 min read

Seed starting for hydroponics

Rockwool, rapid rooters, and peat plugs each have trade-offs. How to germinate seeds for hydro transplant with reliable germination rates by crop.

Hydroponics 5 min read

Summer heat and hydroponic reservoirs

Warm nutrient solution holds less oxygen and breeds more pathogens. Chilling methods ranked by cost, effectiveness, and system size.

Hydroponics 5 min read

Building a vertical hydroponic tower

A PVC tower with net cups and a small pump grows 20-30 plants in under half a square meter. Materials, sizing, and which crops actually work vertically.

Hydroponics 5 min read

Water quality for hydroponics

Hard water, soft water, well water, city water. What's in your tap affects everything you add after. When to filter and when to work with what you've got.