Dosatron Nutrient Delivery System Monitor Kit – 3/4 Inch

The Dosatron Nutrient Delivery System Monitor Kit – 3/4 Inch (SKU HYKMON, Lo-Flo configuration) is the in-line monitoring stage of the Dosatron Nutrient Delivery System. Installed after the mixing chamber on the 3/4 in. NPT supply line, the kit provides constant, real-time readings of EC/ppm, pH, and temperature so growers can confirm the dosed solution actually leaving for the crop matches the recipe. The kit ships with the monitor, EC/ppm, pH, and temperature probes, a mixing chamber, pressure gauge, ball valves, check valve, and all plumbing connections needed to install into a Dosatron injector system rated for up to 14 GPM.

Dosatron Nutrient Delivery System Monitor Kit Specifications

Specifications below are drawn from the canonical Cultivate Supply listing for the Dilution Solutions Nutrient Delivery System Monitoring Kit (HYKMON), supplemented by the matching Lo-Flo configuration documentation published on hydrobuilder.com, thehydrobros.com, and hortitechdirect.com.

Specification	Value
Manufacturer	Dosatron (Dilution Solutions NDS line)
Model / SKU	HYKMON (Lo-Flo Monitor Kit)
Connection Size	3/4 in. NPT
Maximum Flow	14 GPM (Lo-Flo)
Measured Parameters	EC / ppm (electrical conductivity), pH, solution temperature
Display	In-line monitor with easy-to-read display, constant real-time readings
Probes Included	In-line EC/ppm probe, pH probe, temperature probe
Kit Contents	Monitor with probes, mixing chamber, probe holder assembly, union, close nipples, nipples, tee, pressure gauge tee, pressure gauge, cross, check valve, ball valves, fittings, hose adapter, Teflon tape
Shipping Weight	10.41 lb
Assembly	Required (plumbing assembly + probe installation)
System Role	In-line monitoring stage of the Dosatron Nutrient Delivery System (paired with Starter Kit, Mixing Chamber Kit(s), and Water Hammer Arrestor Kit)
Larger Sibling	Hi-Flo Monitor Kit at 1-1/2 in. NPT for higher-throughput commercial systems

Why Choose the Dosatron Monitor Kit

A Dosatron injector mixes concentrate into the supply line by a fixed ratio — the dosing accuracy is mechanical and repeatable. What the injector cannot tell you is whether the resulting blend at any given moment is on-recipe for the crop. That is the role of the Monitor Kit, and it is why the kit is the recommended fourth stage in a complete NDS build.

• Confirms the actual solution leaving for the crop. Per Dosatron’s product literature, the kit “will give growers confidence that their plants will receive the proper nutrition they require.” By installing the in-line monitor immediately after the mixing chamber, the grower sees the EC/ppm, pH, and temperature of the dosed solution as it actually exists on the way to the irrigation manifold. That is a different and more useful measurement than reading the concentrate tank or the post-irrigation runoff.
• Three readings on one display. EC/ppm, pH, and temperature are the three parameters that determine whether a hydroponic feed is in spec. Putting all three on a single in-line monitor at one location removes the back-and-forth of carrying handheld meters around the irrigation room. Anyone walking past the manifold can read the current state of the feed at a glance.
• Complete drop-in plumbing. The kit is not just the monitor head. It ships with the mixing chamber, probe holder, union, nipples, tee, cross, pressure gauge with its own tee, check valve, ball valves, hose adapter, fittings, and Teflon tape — every component needed to splice the monitor into a 3/4 in. NPT supply line downstream of the Dosatron injector(s). There is no separate parts-sourcing trip to a plumbing supplier for the install.
• Sized for Lo-Flo Dosatron installations. The 3/4 in. NPT configuration is rated to 14 GPM, which matches the flow envelope of the Lo-Flo Dosatron injector lines used in nursery, greenhouse, and indoor production environments. For higher-throughput commercial systems, Dosatron offers the same monitoring stage in the Hi-Flo kit at 1-1/2 in. NPT.
• Pairs with a water-powered injector platform. The Dosatron injectors that feed the monitor are themselves water-powered — no electricity is required to run the dosing pumps. The monitor head needs power only for its own display and probe circuitry. The combined system runs on the water that the irrigation line is already delivering, which simplifies installation in pump houses, greenhouses, and outdoor manifold cabinets where AC power may be limited.
• Probe maintenance is the only recurring cost. pH and EC probes are consumables. The Monitor Kit ships with all probes installed, and standard pH and EC probe maintenance and calibration kits apply — the same calibration practice growers use on handheld meters. There are no proprietary cartridges or licensed software fees in the loop.

Best Uses for the Monitor Kit

The Monitor Kit is purchased as part of a Dosatron Nutrient Delivery System build. The applications below cover the production environments where in-line EC/ppm, pH, and temperature monitoring of the dosed feed pays back in crop quality and operator time.

• Indoor cultivation rooms running multi-part nutrient programs. When the Dosatron injectors are blending two or more concentrates (A and B parts, supplements, pH buffers) into the supply line at the same time, the resulting EC and pH at the manifold depend on the combined dosing of all injectors at their individual ratios. The Monitor Kit places a single point of truth at the manifold for the actual blend, downstream of all injectors and the mixing chamber. That removes the need to back-calculate the expected blend from individual injector settings.
• Greenhouse and nursery irrigation manifolds up to 14 GPM. The 3/4 in. NPT Lo-Flo configuration suits greenhouse bench feeds, propagation tables, and small-to-mid nursery irrigation manifolds operating within the 14 GPM envelope. The constant-read monitor lets growers verify recipe compliance without pulling handheld meters into wet, cluttered greenhouse aisles.
• Commercial growers who batch-change recipes through the season. Production sites that shift recipes between vegetative, transition, and flowering stages need an on-line check that the new recipe has actually established at the manifold after a tank changeover. The in-line monitor confirms the new EC/ppm and pH within minutes of bringing the new concentrate online, instead of waiting for runoff sampling.
• Multi-zone facilities with one central injector station. Facilities that feed multiple zones from a single Dosatron injector station benefit from a centralized monitor at the manifold. Anyone walking the manifold can confirm the feed at any moment, regardless of which downstream zone is running. The Monitor Kit ships with all the fittings (union, ball valves, check valve, tee, cross) needed to splice into a multi-zone manifold without custom plumbing.
• Reservoir-fed irrigation systems that need source-water QA. Even when source water is pre-treated, EC drift, temperature variation, and pH shift between tanks can affect recipe accuracy. Operators that pull source water through a treatment train such as a compact reverse osmosis system upstream of the Dosatron injectors can use the Monitor Kit to verify the post-blend EC/ppm and pH after dosing.
• Operations standardizing on Dosatron parts and calibration practice. Sites that already calibrate Apera or Bluelab handheld meters can fold the in-line monitor into their existing probe-maintenance schedule. Standard EC calibration solutions and pH buffers apply, and replacement probe heads are sold by typical hydroponic instrumentation suppliers. The probes in the Monitor Kit are not proprietary cartridges.

Dosatron Monitor Kit vs Hi-Flo Monitor Kit and Standalone Probes

There are two natural points of comparison for the 3/4 in. Lo-Flo Monitor Kit: the 1-1/2 in. Hi-Flo Monitor Kit (the same product at a larger pipe size for higher flows), and standalone in-line monitor units that some growers consider piecing together from individual probes and a display head. The differences come down to flow rating, included plumbing, and total installed cost.

Lo-Flo (3/4 in., HYKMON) vs Hi-Flo (1-1/2 in.) Monitor Kits. The two kits perform the same measurement function — EC/ppm, pH, and temperature on the dosed solution — but at different pipe sizes and flow envelopes. The Lo-Flo kit at 3/4 in. NPT is rated for up to 14 GPM and is the right choice for nursery, greenhouse, and indoor production manifolds that stay inside that flow envelope. The Hi-Flo kit at 1-1/2 in. NPT is the right choice for higher-throughput commercial facilities that exceed Lo-Flo capacity. Choose by the flow rating of the manifold the kit is going into, not by the size of the operation in square feet, because manifold flow is what governs pressure drop across the kit.

Complete kit vs piecing together probes and a display. A standalone in-line monitor head with EC/ppm, pH, and temperature probes can be sourced separately and plumbed into a custom manifold by a skilled installer. The Dosatron Monitor Kit pre-packages the monitor, probes, mixing chamber, pressure gauge, check valve, ball valves, tee, cross, union, nipples, hose adapter, and Teflon tape into a single SKU that drops into a 3/4 in. NPT Dosatron NDS supply line. The trade-off is a known quantity: the kit is one purchase order, one shipping line, one configuration documented by Dosatron, and one warranty path. Piecing together components is feasible if the operation has a strong in-house plumbing crew and an existing parts inventory; for sites without that, the kit is the lower-friction path.

Mixing chamber inclusion. A point that is easy to overlook: the Monitor Kit includes its own mixing chamber. The mixing chamber is what ensures the concentrate is fully blended into the supply water before it reaches the probes, so the monitor reads a homogeneous solution rather than a stratified slug. Pairing the included mixing chamber with the existing Mixing Chamber Kit(s) earlier in the NDS line provides redundant blending for the probes specifically.

Comparison to handheld meters alone. Many growers manage EC and pH with handheld meters and periodic spot checks. Handheld meters remain useful for tank-level QC and runoff sampling. The Monitor Kit complements them rather than replaces them: the in-line monitor reads continuously at the manifold, while the handheld is used to cross-check the monitor on a calibration schedule and to spot-check the reservoir and runoff at other points in the irrigation path. Operators that maintain an Apera GroStar EC calibration kit for handhelds can use the same calibration solutions to verify the in-line monitor.

When the HYKMON Lo-Flo kit is the right purchase: You operate a Dosatron NDS at or below 14 GPM on a 3/4 in. NPT supply line and want a single SKU that adds in-line EC/ppm, pH, and temperature monitoring downstream of the injectors and mixing chamber. When the Hi-Flo kit is the right purchase: Your manifold exceeds 14 GPM and is plumbed at 1-1/2 in. NPT. When a different approach makes sense: The operation is small enough that handheld meters and reservoir-side checks meet QA needs, with no plans to scale.

Compatibility & System Integration

The Monitor Kit is one stage of the Dosatron Nutrient Delivery System. It is not a standalone monitoring solution sold for arbitrary irrigation lines; it is engineered to slot into the NDS architecture at the 3/4 in. NPT pipe size. The compatibility points below cover what it pairs with, what plumbing standards apply, and what to confirm before ordering.

Required companion stages in a complete NDS. Dosatron documents a complete Nutrient Delivery System as four kits plus the injector(s): the Standard Starter Kit (front-end source-water connection and filtration), the Mixing Chamber Kit(s) (in-line static mixing immediately downstream of the injector outlets), the Monitor Kit (this product — in-line EC/ppm, pH, and temperature measurement), and the Water Hammer Arrestor Kit (pressure-spike protection at the back end). The Monitor Kit can be installed without the Water Hammer Arrestor Kit, but a complete system as Dosatron specifies it includes all four.

Dosatron injector compatibility. The Monitor Kit is sized for Lo-Flo Dosatron injector configurations on 3/4 in. NPT lines. Operators running multiple injectors in parallel for multi-part dosing can plumb the kit downstream of the final injector and mixing chamber. The kit’s 14 GPM flow rating governs the maximum throughput regardless of how many injectors feed into the line.

Plumbing standard. All threaded connections on the kit are NPT (ANSI/ASME B1.20.1). PVC schedule 40 male adapters, brass nipples, and steel nipples in 3/4 in. MNPT will mate with the kit’s female ports. Teflon (PTFE) thread tape is included in the kit for sealing the connections; alternative pipe-thread sealant compounds rated for the working fluid are also acceptable. Do not use sealants rated only for gas service.

Probe compatibility. The included probes are an in-line EC/ppm probe, a pH probe, and a temperature probe. Standard EC calibration solutions (1.41 mS/cm, 2.77 mS/cm, and similar reference points) and standard pH buffers (pH 4.0, 7.0, 10.0) apply for calibration. An Apera GroStar replacement EC electrode demonstrates the kind of replaceable probe head that hydroponic instrumentation typically uses; consult the documentation that ships with the Monitor Kit for the exact replacement-probe part numbers Dosatron specifies for HYKMON.

Electrical compatibility. The Dosatron injectors are water-powered and require no electrical supply to operate. The Monitor Kit’s display head and probe circuitry require electrical power for the display and signal conditioning. Plan a clean, dry power feed at the manifold location consistent with the monitor’s documentation.

Operating temperature and water quality. The kit measures solution temperature as one of its three parameters, but operators should still verify that the host pump and downstream equipment are within their own temperature envelopes. For source water with high turbidity, an upstream filtration stage (sediment and/or carbon) extends probe service life by reducing biofilm and particulate fouling on the EC/ppm and pH probe faces.

Usage Guidelines & Probe Care

The Monitor Kit is a passive measurement stage in normal operation — it does not control valves or actuate dosing. Day-to-day operation centers on reading the display, recording the values into the operation’s QA log, and keeping the probes calibrated and clean.

Daily operating routine. Read the monitor display at the start of each irrigation cycle and at the start of each shift. Confirm EC/ppm and pH match the recipe target within the operation’s tolerance band, and confirm solution temperature is in the expected range. Out-of-band readings should trigger a check of the concentrate tanks and the Dosatron injector settings before the cycle continues to run at scale.

Calibration schedule. Calibrate the pH probe against fresh pH 4.0 and 7.0 (and pH 10.0 for high-pH ranges) buffers on a weekly to bi-weekly cadence, or more frequently if readings drift. Calibrate the EC probe against fresh 1.41 mS/cm and/or 2.77 mS/cm reference solution on the same cadence. Document calibration events with date, calibration solution lot, and offset/slope values where the monitor exposes them.

Probe cleaning. Rinse pH and EC probes with reverse-osmosis or distilled water at each calibration. For pH probes, use the manufacturer’s recommended cleaning solution to remove protein and biofilm; do not let pH probes dry out — store with the recommended storage solution between extended downtime periods. For EC probes, scale buildup is the common failure mode; gentle cleaning with the recommended EC cleaning solution restores accuracy.

Reading the temperature value. The temperature reading is useful both as a recipe parameter and as a diagnostic. Sudden temperature jumps at the manifold can indicate a closed valve forcing water to recirculate, a failed source-water cooler, or a tank changeover that introduced water at a different temperature. Track temperature alongside EC and pH in the QA log.

Pressure gauge monitoring. The kit includes a pressure gauge on a dedicated tee. Record the steady-state pressure during normal operation; deviation from that baseline is an early warning of a clogged filter upstream, a partially closed ball valve, or a leak downstream. The pressure gauge is a low-cost diagnostic that complements the EC/pH/temperature readings.

Ball valve and check valve operation. The included ball valves allow the monitor stage to be isolated for probe service without draining the entire NDS line. The check valve prevents back-siphon of dosed solution into the upstream supply when the injectors cycle. Verify the check valve is oriented correctly per the kit documentation; reverse installation will allow back-flow and contaminate source-water lines.

Winterization. In freeze-prone climates, drain the monitor stage and remove the probes for indoor storage before the first hard freeze. Water trapped in the mixing chamber or probe holder can freeze, expand, and crack the housings. Follow the kit documentation for the recommended winterization procedure.

How to Install the Monitor Kit

Installation requires basic plumbing tools, the kit components as shipped, and access to the 3/4 in. NPT supply line downstream of the Dosatron injectors and existing mixing chamber(s). The procedure below is generic; cross-reference the installation documentation that ships with the kit for kit-specific torque values, probe seating instructions, and electrical wiring details.

1. Confirm site compatibility and inventory the kit. Verify the existing NDS supply line is 3/4 in. NPT and that manifold flow stays within the 14 GPM Lo-Flo envelope. Unpack the kit and inventory the contents: monitor head with EC/ppm, pH, and temperature probes, mixing chamber, probe holder assembly, union, close nipples, nipples, tee, pressure gauge tee, pressure gauge, cross, check valve, ball valves, fittings, hose adapter, and Teflon tape. Note any missing or damaged components before starting the install.
2. Plan the install location on the supply line. The Monitor Kit installs downstream of the Dosatron injector(s) and any upstream Mixing Chamber Kit(s), and upstream of the irrigation manifold and any Water Hammer Arrestor Kit. The location should have enough straight pipe to fit the union, mixing chamber, monitor, probe holder, cross, pressure gauge tee, and ball valves in sequence, with service clearance to remove and reinstall probes without disassembling adjacent piping.
3. Depressurize and drain the supply line. Shut off source-water supply to the Dosatron injectors and open a downstream drain or valve to depressurize the section where the kit will be installed. Confirm the line is at zero pressure before cutting or removing existing pipe.
4. Cut in and dry-fit the kit components. Cut the supply line at the planned install location. Dry-fit the kit components in the documented sequence (union, mixing chamber, monitor with probe holder, cross, pressure gauge tee with pressure gauge, ball valves) without thread sealant to confirm orientation, fit, and that the monitor display will face the operator after final assembly. Reorient any component as needed before applying sealant.
5. Apply Teflon tape and assemble threaded connections. Wrap PTFE thread tape clockwise around each male NPT thread — two to three layers, leaving the first thread bare. Hand-tighten each connection, then wrench-tighten an additional 1 to 2 turns. Do not over-torque; NPT seals on the taper, and excess torque can crack PVC fittings or distort the kit’s threaded ports. Confirm the check valve is oriented correctly (flow arrow pointing downstream).
6. Install the probes into the probe holder. Following the kit documentation, install the EC/ppm probe, pH probe, and temperature probe into their respective ports on the probe holder assembly. Confirm O-rings or seal washers are seated correctly. Probes are calibrated and tested before shipment in many cases but should still be verified against fresh calibration solutions before commissioning — see the calibration step below.
7. Connect electrical power to the monitor head. Wire the monitor’s display and signal conditioning head to the documented power source per the kit documentation. Use a clean, dedicated circuit where practical. Keep low-voltage probe signal cables routed away from AC power runs to avoid electrical noise on the readings.
8. Pressurize, leak-check, and bleed air. Slowly open the upstream supply valve to repressurize the section. Inspect every threaded joint for weeping or pressure leaks. If a leak is observed, depressurize, disassemble, clean the threads, reapply Teflon tape, and retighten. Open and close the ball valves to bleed air from the mixing chamber and probe holder so the probes are fully wetted.
9. Calibrate the probes before first production use. With the monitor reading and the probes wetted, calibrate the pH probe against fresh pH 4.0 and pH 7.0 buffers and the EC probe against fresh 1.41 mS/cm and/or 2.77 mS/cm reference solution. Document calibration values in the operation’s QA log. Calibrate against the temperature probe by comparison to a reference thermometer if the monitor exposes a temperature offset.
10. Run a commissioning cycle and verify recipe readings. Energize the Dosatron injectors at their normal recipe settings and run a full irrigation cycle. Verify the monitor reads the expected EC/ppm and pH for the recipe and that solution temperature is in range. Record the steady-state pressure gauge reading as the baseline for future diagnostics. Commissioning is complete when the recipe target, monitor reading, and a handheld spot-check at the manifold all agree within tolerance.

Sources & Further Reading