A liter of ready-to-use working solution, already diluted and sitting in the reservoir, mixed from Terra Aquatica TriPart bottles costs UAH 2.23. The same liter built from single salts on a Cornell University recipe costs UAH 0.16. That is a 14-fold gap, and buying in bulk doesn’t close it: with 5-liter jugs against 25 kg (55 lb) bags, you get UAH 1.44 against UAH 0.10.
With numbers like that, nobody would buy bottles. The catch is that you pay for dry salts up front. A starter kit of eleven salts plus a jewelry scale runs about UAH 1,500. So the real question is how much solution you have to go through before that money comes back. All prices below were taken from prom.ua, Ukraine’s largest marketplace, on September 25, 2026. The ratios carry over to any market where both options sell.
Every price in this article is per liter of finished solution, not concentrate. Concentrates come in different strengths: a liter of TriPart makes about 280 liters of solution, while a liter of Cornell stock, diluted 1:100, makes a hundred. So the price of a liter in the bottle tells you nothing, while the price of a liter in the reservoir compares everything fairly. The stock solution dilution calculator works out how many milliliters of stock your reservoir or injector needs.
Bottled hydroponic nutrients vs dry salts: what we’re comparing
Bottled nutrients. The benchmark is TriPart from Terra Aquatica, formerly GHE Flora Series: three bottles of liquid concentrate, Grow, Micro and Bloom. The dose comes from the manufacturer’s 2025 feeding chart for hydroponics in the growing stage: 1.8 mL Grow, 1.2 mL Micro and 0.6 mL Bloom per liter, 3.6 mL/L in total at EC 1.3-1.8. Later stages call for more concentrate, so our numbers go easy on the bottles.
Dry salts. Each salt carries one or two elements, and you weigh each one separately. We used a published recipe: the modified Sonneveld solution that Cornell’s Controlled Environment Agriculture group says it has used for many years to grow lettuce, leafy greens and spinach. Neil Mattson of Cornell and Cari Peters of J.R. Peters Laboratory published it in “A Recipe for Hydroponic Success.” It delivers 150 ppm nitrogen, 31 phosphorus, 210 potassium, 90 calcium, 24 magnesium and 1 ppm iron.
Here is the recipe per 1,000 liters, next to the original per 100 US gallons:
| Salt | Grams per 1,000 L | Grams per 100 gal | Tank |
|---|---|---|---|
| Calcium nitrate | 486 | 184.0 | A |
| Potassium nitrate | 442 | 167.3 | A |
| Ammonium nitrate | 38 | 14.4 | A |
| Iron DTPA, 11% | 9.1 | 3.5 (3.8 of the 10% grade) | A |
| Magnesium sulfate (Epsom salt) | 246 | 93.1 | B |
| Monopotassium phosphate | 136 | 51.5 | B |
| Boric acid | 0.93 | 0.352 | B |
| Manganese sulfate | 0.77 | 0.290 | B |
| Zinc sulfate | 0.57 | 0.217 | B |
| Copper sulfate | 0.09 | 0.035 | B |
| Sodium molybdate | 0.06 | 0.023 | B |
Cornell’s iron chelate is 10% Fe. The DTPA we found for sale is 11%, so the table uses 9% less of it for the same iron. Tanks A and B matter for concentrates: calcium plus sulfate or phosphate forms an insoluble precipitate. If you add salts straight into a full reservoir, add them one at a time and let each dissolve first. The chemistry is covered in our article on A and B stock solutions.
There’s a middle option too: a ready dry blend such as Valagro Master plus calcium nitrate. We already priced it against Flora Series in the wiki: hydroponic nutrients compared: Masterblend, Jack’s 321 and Flora Series. At today’s prices it comes to UAH 27 per 100 liters retail and UAH 16 in bags.
Nutrient solution cost: what a liter of finished solution costs
| Option | Pack and price | UAH per liter of finished solution | UAH per 100 L of finished solution |
|---|---|---|---|
| TriPart, original | 3 × 0.5 L, UAH 930 | 2.23 | 223 |
| TriPart, original | 3 × 1 L, UAH 1,844 | 2.21 | 221 |
| TriPart, original | 3 × 5 L, UAH 5,998 | 1.44 | 144 |
| “Flora Series analog” | 3 × 1 L, UAH 729 | 0.88 | 88 |
| “Flora Series analog” | 3 × 20 L, UAH 7,590 | 0.46 | 46 |
| Valagro Master + calcium nitrate | 1 kg packs | 0.27 | 27 |
| Single salts | 0.5-1 kg packs | 0.16 | 16 |
| Single salts | 25 kg bags | 0.10 | 10 |
Retail salt prices are ordinary farm-store prices per kilogram: calcium nitrate UAH 84, potassium nitrate 154, monopotassium phosphate 200, magnesium sulfate 58. In 25 kg bags the same salts cost UAH 46, 92, 146 and 45 per kilogram.
Where do the 16 kopecks go? Potassium nitrate takes 42% of the cost, calcium nitrate 25%, monopotassium phosphate 17%, Epsom salt 9%, iron chelate 5%. All five micronutrients together cost under half a hryvnia per 1,000 liters.
Weight explains the 14-fold gap. A thousand liters of solution takes 3.6 liters of concentrate in plastic or 1.36 kg (3 lb) of dry salts in a bag. The concentrate was diluted with water at the factory, and you pay to ship that water, plus the bottles, the filling and the brand.
Dry salt starter kit for hydroponics: what you pay up front
Bottles come in doses sized to your needs. A 3 × 0.5 L kit for UAH 930 makes 417 liters of solution, and you can stop there. Salts don’t work that way: the smallest sensible pack of each one covers thousands of liters, and you need all of them at once.
- calcium nitrate, 1 kg: UAH 84, enough for 2,060 L;
- potassium nitrate, 1 kg: UAH 154, for 2,260 L;
- monopotassium phosphate, 1 kg: UAH 200, for 7,350 L;
- magnesium sulfate, 1 kg: UAH 58, for 4,070 L;
- ammonium nitrate, 1 kg: UAH 76, for 26,000 L;
- iron DTPA 11%, 0.5 kg: UAH 450, for roughly 55,000 L;
- boric acid 100 g, manganese and zinc sulfate 30 g each, copper sulfate 100 g: UAH 48 together;
- sodium molybdate, 100 g: UAH 224, for over 1.5 million liters;
- a jewelry scale that reads to 0.01 g: about UAH 220.
That’s UAH 1,514. Almost half of it goes to two items, iron chelate and molybdate, and a home shelf uses only a few grams of each a year. The rest sits in bags for years, so the bags have to seal: calcium nitrate pulls moisture from the air at 50-60% humidity and cakes into a lump. How to keep salts usable to the last gram is covered in how to store mineral fertilizers.
Micronutrients raise a practical problem. You can’t weigh 0.06 g of molybdate on a scale with 0.01 g steps. Work the other way around: weigh the micros for 10,000 liters at once (9.3 g boric acid, 7.7 g manganese sulfate, 5.7 g zinc sulfate, 0.9 g copper sulfate, 0.6 g molybdate) and dissolve them in one liter of distilled water. Then add 1 mL of that stock per 10 liters of reservoir with a syringe. Keep the iron out of this stock: copper and iron compete for the chelating agent, so store your iron chelate separately. Which form suits your pH is covered in iron chelate: EDTA, DTPA or EDDHA.
When dry salts pay off: the math by volume
The starter kit covers at least 2,000 liters of solution, and calcium nitrate runs out first. Until you’ve used those liters, you’re comparing UAH 1,514 for the kit against what the same volume would cost in bottles. Against small TriPart kits at UAH 2.23 a liter, the kit pays for itself at liter 680.
| Solution per month | TriPart bottles per month | Single salts per month | Kit pays off in |
|---|---|---|---|
| 30 L (a shelf with two trays) | UAH 67 | UAH 5 | 23 months |
| 100 L (a 5-gallon home DWC) | UAH 223 | UAH 16 | 7 months |
| 300 L (a rack of several systems) | UAH 670 | UAH 49 | 10 weeks |
| 2,000 L (small farm, 5 L jugs vs bags) | UAH 2,880 | UAH 208 | the first month |
Count monthly volume with top-ups, not by reservoir size. A 20-liter (5-gallon) reservoir that you change weekly and top up by a third between changes goes through about 100 liters a month.
On a shelf with two trays of microgreens, the kit sits for almost two years, and calcium nitrate in a leaky bag will cake long before then. Here bottled nutrients come out no more expensive overall, even though each liter costs more. From 300 liters a month the question is settled: the kit pays back within a season. For a farm using 2,000 liters, the difference is about UAH 2,670 a month, over UAH 32,000 a year, and that belongs in the cost of goods.
Bottled nutrient benefits: what you get with the bottle
Mattson and Peters say it plainly in the same article: large operations mix from individual salts because they can adjust each one and because buying compounds in bulk can be cheaper, while new and smaller growers find the made-from-scratch method hard to manage. Part of the 14-fold gap pays for work the manufacturer did for you.
Accuracy without a scale. You measure concentrate with a cup or a syringe, and being off by 0.5 mL barely matters. With salts, you weigh the dose for a 5-gallon reservoir to a tenth of a gram, and the micros can’t be weighed at all without a stock.
A chart for each stage. TriPart shifts the ratio of Grow, Micro and Bloom from rooting to fruiting on a ready-made chart. The Cornell recipe is built for leafy greens. To run tomatoes or peppers you need a different recipe and the skill to adapt it. We walked through that logic with the Jack’s 321 recipe, a blend built for fruiting crops. A ready stage-by-stage recipe for peppers, from transplant to harvest, is in our guide to hydroponic peppers.
Water correction. TriPart comes in hard-water (HW) and soft-water (SW) versions, so you make a rough water correction at the store. A single-salt recipe has none: you recalculate it for your water yourself. The Cornell article starts exactly there, with a lab analysis of the source water. Skip that step on hard water and you can end up with excess calcium, and the yellowing between leaf veins will push you toward CalMag, which won’t fix anything here. The reason is in our article on calcium and magnesium deficiency (CalMag). Where to start is in water analysis for hydroponics. To size the acid for your water alkalinity, use the hydroponic acid dosing calculator; it also shows how much nitrogen, phosphorus, or sulfur the acid adds to the recipe.
Purity. The Cornell authors stress that salts should be pure and 100% water-soluble. Garden-center packs make no such promise. If sediment shows up at the bottom of the reservoir even though you mixed in the right order, the salt itself may be the cause. Look for “water-soluble” or a technical grade on the label, not “for garden and vegetables.”
Flora Series (GHE) analogs: are they worth it?
The table has one more step: 3-liter and 60-liter kits sold as “Flora Series analogs.” Dosed like the original, they come to 88 and 46 kopecks per liter, 2.5 to 3 times cheaper than TriPart. The problem is that we couldn’t verify what’s in them. Listings rarely show a full label with micronutrients, and micronutrients are exactly where formulas differ most. We showed this with numbers in the wiki: the Masterblend 4-18-38 lettuce recipe delivers almost eight times as much boron as the Cornell solution.
For a 30-liter-a-month shelf, the risk is small. For a farm, an unknown formula is a poor bet; single salts cost less than any analog, and you weighed every gram in the tank yourself.
Three mistakes when switching to dry salts
Buying the recipe without the micros. Macro salts make up 99% of the weight and 94% of the cost, so it’s tempting to pick up the rest later. Without iron, lettuce shows chlorosis on young leaves; without boron, growing points start to die. Buy the whole kit or none of it.
Mixing salts into one jar for convenience. Calcium nitrate, Epsom salt and monopotassium phosphate react right in the jar once they pick up moisture, and you end up adding partly bound calcium to the tank. Store every salt separately, and keep tanks A and B separate too.
Judging savings by the price per liter instead of your volume. The 14-fold figure holds for every liter, but your monthly volume decides payback. On a two-tray shelf, dry salts take almost two years to pay off, and the kit can go bad before it does.
Which hydroponic nutrients to choose: decide in five minutes
- Work out how much solution you use per month, top-ups included.
- Under 50 liters a month, buy bottled nutrients and skip the scale.
- From 100 liters, buy a dry-salt kit: it pays off in seven months, and after that every liter costs 16 kopecks.
- Before the first mix, test your water and adjust the recipe to it, as described in how to build a nutrient solution recipe. If you’d rather not do the math by hand, our NPK calculator has ready profiles on Yara salts and scales the grams to your reservoir.
Between 50 and 100 liters, the kit pays off in 7 to 14 months, and money stops being the main argument. What decides it is whether you want to learn how recipes work. If you do, dry salts will pay for your education within a year.
