Seedling Formula
✦ Free ForeverExact PPM ramp from dome-off to transplant — sourced from Resh & Van Patten. Stop burning fragile roots with guesswork.
One formula, sprout to transplant
A single 3-part stock set carries your seedlings from dome-off through true leaves to a transplant-ready root system. Switch to a crop-specific formula only once roots are ready for your main system.
EC = PPM ÷ factor. Use 500 (US / Hanna) or 700 (EU / Truncheon) to match your meter.
Mixing steps
Fill your reservoir to the target volume with RO or pre-adjusted water. Never mix concentrates into each other.
Add Stock A — the ml shown above — slowly, stirring until the water runs clear.
Add Stock B to the same reservoir water and stir until clear. Never add it to the Stock A bottle.
Add Stock C last — half the dose of A (e.g. A = 2 ml → C = 1 ml). Stir.
Adjust pH to 5.5–5.8 for seedlings. Verify TDS / EC and top up with plain pH water if slightly high.
Replace the solution fully every 7–10 days. Daily top-ups use plain pH water only — nutrient top-ups raise EC too fast.
Never pour Stock A and Stock B concentrates directly together. Direct contact causes calcium-sulphate precipitation — flakes that plant roots cannot absorb. (Source: Howard M. Resh, Hydroponic Food Production, 7th Ed.)
Frequently asked questions
What is the Megaponics seedling formula?
It's a single 3-part (A/B/C) nutrient stock set that carries hydroponic seedlings from dome-off through true leaves to a transplant-ready root system. You dose it in millilitres per litre of reservoir water, ramping up as the seedling grows.
How much nutrient do hydroponic seedlings need?
Very little at first. Start around 0.5 ml/L (about 100 PPM) when the dome cracks and ramp gradually to about 4 ml/L (roughly 800 PPM) by transplant. Low early doses are intentional — seedling roots are too small to absorb more, and over-feeding burns them.
What pH is best for hydroponic seedlings?
5.5 to 5.8 for most seedlings. Verify EC/TDS after mixing and adjust pH last.
Which salts are in the seedling formula?
Stock A is Calcium Nitrate, Potassium Nitrate and Fe-EDTA chelated iron. Stock B is Mono Potassium Phosphate, Potassium Sulphate and Magnesium Sulphate. Stock C is a chelated micronutrient mix.
What is the TDS meter factor (500 vs 700)?
Different meters convert EC to PPM using different factors. Pick 500 (common on US / Hanna meters) or 700 (common on EU / Truncheon meters) so the PPM shown matches your meter.
Is the seedling calculator free?
Yes — it's 100% free, forever. Create a free account to unlock the full recipe and stage-by-stage doses. No subscription or payment is required.