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pH/ORP Swimming Pool and Spa Controllerswith Built-In Chemical Feed Pumps and Hanna Cloud Connectivity

Hanna Swimming Pool and Spa Controllers are complete systems designed for maintaining swimming pool, hot tub, and spa disinfection water quality. Each model is available in
two configurations. The basic version is the in-line model which allows for direct installation of probe and chemical injection fittings into existing piping. A panel mounted version
with a bypass flow cell is also available. The bypass flow cell allows for calibration and maintenance of the probe without having to shut down the recirculation pump.

For BL121 and BL123 models, three 4-20 mA analog outputs are available for users that wish to connect to an external chart recorder or datalogger to monitor any of the three
measured parameters. The outputs are scalable, offering increased flexibility and better resolution as needed.

BL122 and BL123 also offer the added benefit of allowing remote connection and access to devices via the Hanna Cloud web app. Hanna Cloud application is compatible with most
modern web browsers.

Model Overview

pH/ORP Swimming Pool and Spa Controllers

  • In-line and user panel flow cell configurations available
  • Multiparameter digital pH, ORP, temperature probe included
  • In-line and user panel flow cell configurations available
  • Analog Outputs
  • Multiparameter digital pH, ORP, temperature probe included

pH/ORP Swimming Pool and Spa Controller with Hanna Cloud Connectivity

  • In-line and user panel flow cell configurations available
  • Hanna Cloud Connectivity
  • Ethernet Input
  • Multiparameter digital pH, ORP, temperature probe included
  • In-line and user panel flow cell configurations available
  • Analog outputs
  • Hanna Cloud Connectivity
  • Ethernet Input
  • Multiparameter digital pH, ORP, temperature probe included

Display Modes

The versatile display of these controllers allow for three display modes. The LCD can display all three parameters at one time, a 3-second cycle of single parameters, or a real-time plot screen with options for parameter selection, zooming, and log recall.

Three Parameters on Display
3-Second Single Parameter Cycle Display
Real-time Plot Display

General Features

Adjustable Flow Rate

The dosing pump flow rate is adjustable from 0.5 to 3.5L/h. Larger bodies of water require more chemical to be dosed than small bodies since it takes more chemical to see a change in the reading. The adjustable flow rate, like the proportional band, allows for better control in maintaining a desired set point.

Acid and Chlorine Tank Level Inputs

These controllers allow for a connection to an optional level controller. This input is used to disable the dosing pumps when there is no chemical left in the reservoir tank.

Hold Input

It is possible to connect a flow switch mounted in-line or a mechanical relay that is connected to the recirculation pump power source to the hold input of these controllers. With no flow or when no power is applied to the recirculation pump, the hold circuit will disable the dosing pumps. This will prevent any dosing of chemical when there is no movement of water in the system.

ORP (Chlorine) Dosing Consent

Both pH and ORP meters are commonly used with swimming pools. With chlorine disinfection there is an inverse relationship between pH and ORP. As the pH level increases, the ORP level decreases. These meters utilize a dosing consent feature that will not dose chlorine until the pH value is first corrected since it is possible to have a low ORP value even though there is sufficient chlorine. The dosing consent feature prevents waste of chemicals and avoids having a higher chlorine concentration level than desired.

Automatic Proportional Pump Control

Based on the sensitivity of the process to chemical addition, these controllers allow the user to adjust a proportional band. This setting determines the amount of time that the pumps are dosing as a percentage of the deviation from the set point. For example, a large body of water will use a small proportional band; having a small band (e.g., 0.1 pH) will ensure the pumps are dosing more often when the reading is close to the set point. For smaller bodies of water such as hot tubs or spas, it is more useful to set a larger proportional band (e.g.,1.0 pH); when the reading is close to the set point, the amount of time that the dosing pump is on is minimal to avoid large swings of pH or ORP. This valuable feature allows for very fine control in maintaining the desired set point.


BL121 and BL123 Analog Inputs

BL121 and BL123 controllers offer three 4-20 mA outputs. Each output can be disabled or connected to an external recording device. Each of the three measured parameters (pH, ORP, and temperature) can be assigned to an analog output where the current signal will be proportional to the measured value. For more flexibility and better resolution, the analog output can be scaled; users can define any two points within a parameter range to correspond to the analog output span. For example, the controller assigns 0 pH to 4 mA and 14 pH to 20 mA as a default. The user can adjust the pH range to assign pH 6 to 4 mA and pH 8 to 20 mA. This adjustment allows better resolution in the range of interest.

Multiparameter Digital pH, ORP, Temperature Probe

The HI1036-1802 is a digital combined probe that measures pH, ORP, and temperature. This probe also incorporates a potential matching pin. The matching pin is considered the “earth ground” connection and is used to prevent ground loop effects from causing erratic readings and damage to the system.

The HI1036-1802 with a Hanna Swimming Pool and Spa Controller helps to promote the health and safety of pool and spa water.

Keep Track Anywhere with Hanna Cloud Connectivity (BL122 and BL123)


Hanna Cloud is a web based application that connects you to the BL122 and BL123 controllers. Measurements and data storage are accessible from your PC, tablet or phone. Multiple registered devices may be connected to Hanna Cloud.

Measurements, trends, history, device settings, alarms and messages are transmitted to your “Dashboard” as your instrument measures and controls your process. Multiple secondary users may also be added to your device account to monitor measurements and receive email or pop-up messages from your process device.

Configure BL122 and BL123 for Hanna Cloud Connectivity


Configure your settings for cloud connectivity

R-HOLD (Remote Hold)

The reagent pumps can be turned off using the Remote Hold feature from Hanna Cloud. They can be reactivated at the controller or through Hanna Cloud.

Hanna Cloud Options

Choose from static or DHCP connection

Hanna Cloud Features

Measurement, alarm, hold and pump status are easily available

Select which notifications you would like to receive

Use a graph to view trends over the last 12 hours or change the time period

Calibration and Maintenance