Hydroponic Plant Food
Hydroponic plant food for herbs, greens, and houseplants grown without soil. Clean, complete nutrition that mixes into water in seconds.
Mix it into your reservoir or feedwater as directed for a straightforward nutrition routine that keeps hydroponic feeding easier to manage.
Made by growers
More than a bottle on a shelf.
- Talk to real plant people. The team that mixes the formula answers your email.
- Made in-house, in the USA. Every bottle mixed and filled by us, not a third party.
- We're growers, not resellers. We use this on our own plants before it ships.
- Bundle savings only here. Pair any two TPS formulas — your order ships free.
Hydroponic Plant Food with a complete, potassium-forward 4-3-6 NPK plus iron and a full micro package — made to be the only nutrition plants get when they're grown in water instead of soil. Because a soilless plant draws everything directly from the water, this feeds all of it in one bottle: nitrogen for leaves, phosphorus for roots, potassium for fruit, and the calcium, magnesium, and micros that soil would normally supply.
How to Use Hydroponic Plant Food
| Method | Amount | How Often |
|---|---|---|
| Hydroponic systems | 5 mL (1 tsp) per quart of feedwater | Leafy plants: every 2 weeks; Fruiting plants: weekly |
| Seed pod systems | 5 mL (1 tsp) per 3 standard growing pods, at the start and again as needed | As needed |
Add to your hydroponic feedwater or reservoir, not to soil. For best growth keep the water at pH 5.0-6.0, and be careful not to overfeed.
What's Inside
The 4-3-6 ratio is a complete, potassium-led formula built to stand alone in a soilless system — with no soil to store nutrients or supply trace minerals, the feed has to carry everything the plant needs. The 4% nitrogen supports leaf growth, the 3% phosphate builds roots and backs fruiting, and the 6% potash drives fruit quality and vigor. The nitrogen is split between nitrate, absorbed directly for a quick response, and a smaller ammoniacal and urea fraction for steadier feeding through the growth cycle.
Beyond NPK: sea kelp (Ascophyllum nodosum) for natural growth compounds, plus 1.0% calcium and 0.5% magnesium and a full micronutrient package — iron, sulfur, manganese, zinc, boron, and copper. These matter more in water culture than in soil, because the plant has no reserve to draw on: iron prevents new-growth yellowing, and calcium and magnesium head off the tip-burn and interveinal yellowing that appear fast in hydroponics. Keeping the water near pH 5.0-6.0 is what lets roots actually absorb the full package.
Made For
Built for plants grown hydroponically or in soilless setups — lettuce, herbs, and leafy greens in countertop seed-pod gardens, deep-water culture, Kratky jars, and NFT systems, plus fruiting crops like tomatoes and peppers grown in water.
Problems It Solves
- New growth yellowing in a soilless system
- Tip burn or interveinal yellowing on hydroponic crops
- Slow, weak growth in a countertop or reservoir garden
- Plants that stall because the water lacks trace minerals
FAQs
How often should I add hydroponic plant food?
Add 5 mL (1 tsp) per quart of feedwater — for leafy plants every 2 weeks, for fruiting plants weekly, since fruiting crops use more. In seed-pod systems, add 5 mL for every 3 growing pods at the start and again as needed. Warmer, brighter, faster-growing conditions burn through nutrients quicker, so keep the reservoir topped up on schedule and don't let it run dry between feedings.
Can this be the only fertilizer for my hydroponic garden?
Yes — that's what it's designed for. It's a complete formula with nitrogen, phosphorus, potassium, plus calcium, magnesium, and a full micro package, so a soilless plant can draw everything it needs from it. That completeness matters in hydroponics, where there's no soil to fill gaps: a fertilizer missing calcium, magnesium, or iron would leave plants deficient fast. Just keep the water at pH 5.0-6.0 so the roots can take all of it up.
What pH should the water be?
Aim for pH 5.0-6.0. In that range most nutrients stay available to roots in water culture; drift outside it and plants can't absorb certain nutrients even though they're dissolved right there, which looks like a deficiency despite regular feeding. Check pH with a meter or test kit and adjust with pH up or down. In hydroponics, managing pH is as important as the nutrient dose — the two together determine whether the plant can actually feed.
Is this good for a countertop seed-pod garden?
Yes. For seed-pod systems, add 5 mL for every 3 growing pods at the start and again as needed; for other hydroponic setups, use 5 mL per quart of feedwater. Countertop gardens are small, so the water changes concentration quickly as plants drink it down — keep an eye on the level and refresh on schedule. These systems make hydroponics beginner-friendly, and a complete plant food like this covers the nutrition side simply.
When will I see results?
Hydroponic plants often grow quickly once nutrition and pH are dialed in, with leafy greens showing new growth within days to a couple of weeks. With no soil buffer they respond fast to good conditions and to bad ones, so consistent feeding and pH keep growth steady. Fruiting crops follow their own cycle over the following weeks as they flower and set fruit. Existing damage won't reverse, so you're feeding the new growth.