Hypochlorous Acid by the Gallon: What It Costs to Make vs Buy Bottled

Searches for a hypochlorous acid gallon usually turn up bottled product sold by volume. HOCL LLC does not sell bottled HOCl; it sells machines, including the Eco One, that make a measured batch from water, salt and vinegar. This article works the cost comparison in two units—per liter and per gallon—so a “gallon” shopping query can be lined up against a 1-liter home batch. Every price below is a dated retail listing as of Nov 10, 2026, and the math is shown so you can redo it with your own prices.

The units, first

US liquid gallons and liters convert as:

1 US gallon = 3.785411784 liters (exactly, by definition of the US gallon).

All “per gallon” figures below are “per liter × 3.785411784,” rounded only at the last step.

A 200 ppm Eco One batch is 1 liter. To compare that batch with a bottled gallon, multiply the per-liter cost by 3.785411784, or divide a bottled gallon price by the same factor to get a per-liter price.

Bottled hypochlorous acid, as of Nov 10, 2026

Bottled hypochlorous acid on Amazon, checked November 10, 2026 (prices before tax; shipping varies):

Per liter = price ÷ liters (1 US gallon = 3.785411784 L; 1 US fl oz = 29.5735 mL). Gallon and larger sizes ran about $5.81–$9.77 per liter ($22.00–$36.99 per gallon); a 32 oz bottle was about $19 per liter.

This is a price-per-liter comparison only. Bottled products differ in concentration, pH, ingredients and label directions. A batch you make is not the same product as any bottled HOCl, and it does not carry any bottled product’s label or claims.

What “made” costs with the Eco One

A made liter is not one number. It is at least two layers:

1. Consumables per liter — salt, vinegar, water and electricity for that run.
2. Machine cost spread over the liters you actually make — the purchase price divided by cumulative output.

The Eco One manual’s directions for a 200 ppm liter are the input amounts this math uses:

• Volume: 1 L (fill the 1.5 L pitcher to the 1 L line)
• Salt: 2 g food-grade, non-iodized kosher salt
• Vinegar: 1 teaspoon of 5% distilled vinegar
• Run time: 16 minutes (Setting 3 run twice)
• Water: 1 L, hardness under 80 ppm recommended

The Eco One’s list price on store.hocl.com/ecoone was US $199.99 as of Nov 10, 2026.

Layer 1 — consumables, as of Nov 10, 2026

Write each input as amount × unit price.

Salt. 2 g = 0.002 kg per liter. A 3 lb (1.361 kg) box of coarse kosher salt was $3.97 on November 10, 2026, or $2.92 per kg. Cost per liter: 0.002 × $2.92 = $0.006.

Vinegar. 1 teaspoon is 4.92892 mL in the US, often treated as 5 mL for kitchen math. Using 4.93 mL: a 1-gallon jug of 5% distilled white vinegar was $3.94 at one retailer and $12.82 for a different brand on Amazon on November 10, 2026—$1.04 to $3.39 per liter. Cost per 200 ppm liter (1 tsp): $0.005–$0.017. Per 500 ppm liter (2 tsp): $0.010–$0.033.

Water. 1 L of tap or purified water. Water cost depends on your utility and isn’t itemized here.

Electricity. Electricity can’t be priced here because the Eco One’s wattage isn’t published. The manual and the product page do not state a watt rating, so electricity is left out of the per-liter figures below.

Consumables per liter (salt plus vinegar only):

Salt plus vinegar for a 200 ppm liter came to $0.011–$0.023 per liter (about 4–9 cents per gallon) at those prices; a 500 ppm liter came to $0.016–$0.039 per liter (about 6–15 cents per gallon). Those figures leave out electricity, water and the machine itself.

Salt and vinegar alone come to a few cents per liter. Your total per liter also includes the machine price spread over the batches you make (table below) and electricity, which isn’t priced here. Gallon-and-larger bottled listings above ran $5.81–$9.77 per liter on Nov 10, 2026.

Layer 2 — spreading out the machine price

If P is the machine price and N is the number of 1 L batches you actually run:

Cost_machine ($/L) = P / N

Cost_machine ($/gal) = (P / N) × 3.785411784

Using the November 10, 2026 list price of $199.99, here are example machine shares if you spread that price over 100, 500, or 1,000 liters. These are reader-adjustable examples, not a claim about how long a machine lasts or how many liters it will make:

(Values are $199.99 ÷ N, and that result × 3.785411784. Substitute any N you want.)

These rows are arithmetic only. They are not a statement of how many batches an Eco One will make; this guide states no guaranteed cell life.

Total made cost:

Cost_made ($/L) = Cost_consumables + Cost_machine

Cost_made ($/gal) = Cost_made ($/L) × 3.785411784

Add the machine share for the number of liters you expect to make to the few cents of salt and vinegar per liter. At 1,000 liters, for example, that’s $0.20 + about $0.01–$0.02 per 200 ppm liter, before electricity.

What this comparison leaves out

• Shipping, tax and destination duties on either a bottled jug or the Eco One.
• Test paper and spray bottles, which you may already have; replacement test paper is a separate item.
• Time. A 200 ppm liter is a 16-minute run plus testing and transfer.
• A 500 ppm Eco One run (40 minutes, 2 tsp of 5% distilled vinegar) uses different time and vinegar amounts; the consumable range for that mode is given above.
• Concentration. The bottled listings above range from 0.018% to about 500 ppm; compare a 500 ppm Eco One run with the 500 ppm listings.
• Any use, performance or “worth it” claim. This page is arithmetic.

For the run itself, see How to Make Hypochlorous Acid at Home. For model differences, see Choosing an HOCl Generator. To make liters at home with a machine, start with the Eco One or the HOCl bundle.