This page walks the water from the well to the pallet. Each application has a different demand profile, a different set point, a different rule and a different failure mode — and treating them as one system with one number is the most common reason a farm installation disappoints. Read it alongside the implementation page, which turns these into written procedures.
About claims on this page
EcoloxTech generators produce a hypochlorous acid solution on site. They are regulated by the EPA as devices, are not registered disinfectants, and we make no efficacy claims for them or for the solution they produce. The only EcoloxTech product with disinfection claims is HOCl-AS200 (EPA Reg. No. 101112-1), used according to its label. Research cited here describes published studies of hypochlorous acid and electrolysed water under their own test conditions; it is not a claim for any product.
Start at the source
Before any application, the source water decides what is possible. A surface source — river, canal, pond, reservoir — carries organic load, seasonal variability and, under 112.44(a), a prohibition on untreated use for the highest-risk purposes. A well is more stable but can carry iron, manganese and hardness that matter more to a generator than a grower expects. Municipal supply arrives with a residual already in it.
| Source characteristic | Why it matters | What to do about it |
|---|---|---|
| Organic load / turbidity | Exerts continuous chlorine demand; shields organisms; fouls equipment | Filtration and settling before dosing, not more dosing |
| Hardness | Scale on cell surfaces and in lines; reduces cell life | Water analysis first; softening or conditioning where indicated |
| Iron and manganese | Consumed by oxidiser, causes staining and emitter fouling | Pre-treatment. This is a water chemistry job before it is a generator job |
| pH | Governs the hypochlorous acid / hypochlorite balance in the treated water | Measure it. Do not assume it is stable across the season |
| Seasonal variability | A surface source in spring is not the same water as in August | Reassess; the 112.43 assessment is annual for a reason |
| Existing residual (municipal) | Changes the demand calculation | Measure at the point of use, dose to the gap |
A single sentence saves a great deal of trouble: get a full water analysis before specifying equipment. Not a pH strip — a laboratory analysis covering hardness, iron, manganese, alkalinity, TDS and organic load. The answer to “why is my cell fouling” is almost always in a report nobody commissioned.
Irrigation and fertigation
Injecting into an irrigation system is the application with the largest agronomic upside and the most engineering detail. The objectives are usually stated as keeping lines and emitters clear, limiting biofilm and algae, and managing waterborne root pathogens.
| System type | What it asks of the treatment | Notes |
|---|---|---|
| Drip / micro-irrigation | A residual carried the length of the run, past the last emitter | Low flow, long residence time, small orifices. The clogging case is strongest here |
| Overhead sprinkler | Water quality at application; direct contact with edible portions of some crops | 112.44(b) or (c) depending on crop and timing; the contact question is real |
| Fertigation | Compatibility with injected nutrients | Never inject an oxidiser and a nutrient concentrate at the same point. Separate injection points and sequencing |
| Reservoirs and holding ponds | Bulk treatment and algae control | Huge volumes, high demand, sunlight-driven decay. Often better addressed by covering and turnover |
| Filtration stations | Keeping sand, disc and screen filters from becoming biofilm reservoirs | Backflush schedule matters as much as dosing |
Three operational rules apply across all of them. Measure at the far end, because a set point at the injection skid tells you nothing about what reached the last emitter on the longest run. Never mix injection streams — oxidiser and nutrient concentrate meeting at high concentration in a header is a chemistry problem and sometimes a safety one. And clean before you maintain: a fouled line needs flushing and usually an acid treatment before a residual programme means anything.
The research in the hub closest to this application is electrolytically generated chlorine injected into citrus micro-irrigation systems, on injecting electrolytically generated chlorine into citrus micro-irrigation for waterborne root pathogens, described as research under its own conditions.
Greenhouse and recirculating systems
Recirculation is where disinfection stops being optional. Collecting and returning nutrient solution is excellent water and fertiliser economics and a highly efficient way to distribute a root pathogen to every plant in the house. Growers who move to recirculation almost always add a disinfection step within a season or two, usually after losing a crop.
| System | Where the treatment sits | Watch for |
|---|---|---|
| NFT | On the return, before the mixing tank | Thin film, continuous flow, fast pathogen spread. Demand from root exudate is significant |
| Ebb and flood / flood floor | On the return to the holding tank | Floors and gutters are biofilm habitat; the tank is not the whole system |
| Substrate culture with drain capture | On the captured drain before reuse | Drain water carries the highest organic load in the system |
| Deep water culture | In-loop, with careful attention to root health | Roots sit in the treated water. Concentration tolerance is crop-specific and needs trialling |
| Propagation and nursery benches | Bench and floor sanitation, tool dips, misting water | Young plants are the most vulnerable stage and the cheapest to protect |
Two questions must be settled before injection, not after. The first is nutrient compatibility: oxidising chemistry can interact with chelated micronutrients, iron chelates especially, and the answer depends on the specific formulation. Ask your nutrient supplier directly. The second is crop tolerance: root tissue sitting in treated solution is not the same exposure as a wash step, and tolerance varies by species and growth stage. Trial on a bench or a single house before committing the site. The comparative work in the hub, in-situ electrochemical hypochlorination compared with conventional water disinfection in recirculating hydroponics, is the relevant published starting point.
Harvest: tools, containers and field stations
Harvest is where a clean crop most often becomes a contaminated one, and almost none of it is about water treatment chemistry. It is about knives, bins, gloves, trailers and toilets.
| Item | What good practice looks like |
|---|---|
| Harvest containers and bins | A defined cleaning and sanitising routine with a recorded frequency. Food-contact surfaces under 21 CFR 178.1010. Bins that go to the field and come back are a two-way route |
| Knives and cutting tools | Dip stations with a maintained solution and a change-out rule. For bacterial and viral plant pathogens, tool sanitation matters as much as water treatment |
| Gloves and aprons | Cleanable or single-use, with a written rule about what happens after a break |
| Hand-washing stations | Water meeting 112.44(a) for hand washing during and after harvest; soap, single-use towels, adequate number and placement |
| Field-pack sprays | Water applied to harvested crops before cooling falls under 112.44(a). Treat it accordingly |
| Trailers and transport | Cleaned between loads, particularly where the same trailers carry inputs and product |
Dump tanks, flumes and wash lines
This is the highest-leverage water on the site and the hardest to hold. Organic load arrives continuously with the product, and the residual falls unless something is maintaining it against that demand.
The rule to work from is FCN 1811, covering hypochlorous acid in process water or ice contacting fruits and vegetables at a free available chlorine level not exceeding 60 ppm, with draining or a potable rinse where the product is consumed raw. 21 CFR 173.315 governs chlorine compounds used in washing fruits and vegetables and requires a potable rinse. Confirm the current text of both before setting internal limits.
| Control | Why it decides the outcome |
|---|---|
| Continuous residual monitoring | The number changes minute to minute with load. Spot checks every few hours describe a system you are not actually running |
| Water turnover | Dilution of organic load is a control in its own right. Dosing harder into exhausted water is not a substitute |
| Filtration | Removes the soil and debris that create the demand in the first place |
| Temperature differential | Product warmer than the water can draw water into the tissue. This is a food safety control that no chemistry replaces |
| pH control | Governs the chemistry; drifts as organic acids accumulate through the day |
| Change-out rule | A written trigger, not a judgement call at the end of a long shift |
Published work on produce washing in the hub includes decontamination of lettuce using acidic electrolysed water, pathogen reduction and quality of lettuce treated with electrolysed oxidising and acidified chlorinated water and the broader a review of electrolysed water as an alternative to sodium hypochlorite for fruits and vegetables. The consistent message across the literature is worth repeating here: wash water treatment is cross-contamination control, not decontamination. It stops one dirty item from contaminating a day’s pack. It does not sterilise produce, and no responsible programme is built as if it did.
Hydrocooling, ice and cold chain
Cooling water and ice deserve their own attention because they contact product at the moment it is most vulnerable and in the largest volumes. Ice contacting covered produce falls under 112.44(a), and FCN 1811 covers hypochlorous acid in ice as well as in process water.
Cold water holds a residual better than warm, which helps. What does not help is the infiltration risk at the point where warm product meets cold water — the same mechanism as in the wash step, and the reason cooling water quality is a food safety control and not simply a quality one. Operations running their own ice should treat the ice machine and its water as part of the food safety programme rather than as plant utilities, including the cleaning schedule for the machine itself.
Packhouse surfaces and the sanitation round
Everything after the wash line is standard food-contact sanitation under 21 CFR 178.1010: sanitising solutions at not more than 200 ppm with adequate draining before food contact. Belts, brush beds, rollers, graders, sizers, tables, tote lines, packing benches and the floors and drains around them.
The packhouse-specific point is Listeria harbourage. Hollow rollers, worn belting, standing water under equipment, drains and condensate above the line are where it persists, and none of those are reached by a wash-down of the visible surfaces. A sanitation programme that takes equipment apart on a defined cycle, combined with a zoned environmental monitoring programme, is what actually controls it. The chemistry is the easy part.
Tool dips, and the application everyone forgets
For bacterial and viral plant pathogens, tools and hands matter as much as water. A single infected plant, a knife and an afternoon of pruning is a well-documented way to move a bacterial canker or a mechanically transmitted virus through a house. Growers who treat water diligently and tools casually are protecting one route and leaving another open.
A working dip station is unremarkable: a maintained solution at a defined strength, a change-out rule based on visible soiling and elapsed time rather than intuition, a station within reach of where cutting actually happens, and a rule that the tool goes in the dip between plants or between rows depending on the crop and the pathogen. The failure modes are equally unremarkable — a dip left from last week, a station too far away to use, or a solution so loaded with sap that it has become a transfer medium rather than a control.
Field stations and the harvest crew
Harvest hygiene is where a great deal of the Produce Safety Rule actually lands, and it is mostly about provision rather than chemistry. Enough toilets, close enough to the crew, kept stocked and clean. Hand-washing stations with water meeting the 112.44(a) criterion, soap and single-use towels, positioned so that using them does not cost a worker their place in the row. A written exclusion policy for ill workers that supervisors apply consistently, and that the crew has been told about in a language they speak.
The practical test of a harvest hygiene programme is simple: watch a crew for an hour. If stations are too far away, or too unpleasant to use, or if stopping to use them is visibly penalised by the piece rate, then the programme exists on paper only. That observation is worth more than another page of procedure.