NanoDose™ Standalone pH Control Recirculation Kit

Installation Instructions

For an incoming raw water line emptying into a tank, the best approach is to measure the pH inside the tank or use a recirculation loop rather than measuring directly on the incoming pipe.

• Measuring on a one-way incoming line creates a major problem: the pump will dose chemical into the pipe, but the water will rush into the tank before the chemical has time to mix and change the pH.
• The probe will never read the true, reacted pH, causing the pump to over-dose or under-dose constantly.

Here is how you should set up your NanoDose™ pH Control Recirculation Kit:

Option 1: The Cyclical (Recirculation) Setup — Highly Recommended

This is the most accurate and reliable method for automated pH control.

• The Layout: The best way is to use our NanoDose™ pH Control Recirculation Kit , which is mounted onto the side of your water tank and consists of a dedicated recirculation pump that continuously pulls water out of the tank, passes it through an external pipe loop, and dumps it back into the tank.
• Probe Placement: The pH probe is then installed in the external recirculation line.
• Injection Placement: The pump's injection valve is installed into the venturi injector directly into the top of the tank away from the suction point at the bottom of the tank.
• Why it works: The water in the tank is constantly mixed, giving the probe a highly accurate, stable reading of the actual water quality.

Option 2: Measuring Inside the Tank

If a cyclical loop is too complex, you can measure directly inside the storage tank.

• Probe Placement: Use a specialized submersible probe holder (an extension rod) to hang the pH probe directly inside the tank. Place it at a medium depth, away from the incoming raw water splash zone.
• Injection Placement: Run the dosing tube to drop the chemical directly into the tank right where the incoming raw water enters. The turbulence from the incoming pipe will help mix the chemical.
• Why it works: It ensures the pump responds to the total volume of water, though you must ensure the tank has enough natural agitation (or a mechanical mixer) so the chemical distributes evenly.

Connection guidelines:

1.  The Recirculation Pump (Always On)

The recirculation pump needs to run continuously (or whenever raw water is entering the tank).

• It is not controlled by the Etatron pump.
• It is not controlled by the chemical float switch.
• Why? If the recirculation pump turns off, the water stops moving. The chemical will pool in one spot, and the pH probe will read stagnant water, causing the system to over-dose or freeze up.

2.  The Float Switch (Controls the Dosing Pump Only)

The float switch included in your kit is a chemical level switch located inside your chemical drum.

• It wires directly into the Etatron pump.
• Its only job: If the chemical drum runs completely empty, the float switch drops, and it tells the Etatron pump to stop firing. This protects the dosing pump from running dry, burning out, or pumping air into the line. It does not affect the water recirculation pump.

3.  How to tie it all together safely

To automate the system safely so it turns off when the main water tank is full, you should use the tank's water level float switch:

• The Main Tank Float Switch: This switch controls the incoming raw water valve or pump.
• The Interlock: You should wire the Recirculation Pump to turn on and off at the exact same time as your incoming raw water supply. When raw water stops filling the tank, the recirculation pump can safely turn off to save power.
• The Etatron Pump: The Etatron pump will simply watch the pH. If the recirculation pump shuts off and the water stops moving, the pH will stay stable, and the Etatron pump will naturally stop dosing on its own.

4.  Sizing the Recirculation Pump

The goal of a chemical recirculation loop is to achieve thorough mixing inside the tank. To ensure the chemical is evenly distributed, the recirculation pump must turn over the entire volume of the tank between 3 to 5 times per hour.

Since your tank range spans from 1,000L to 5,000L, your calculation should target the worst-case scenario (the maximum 5,000L volume) so that one standardized pump size can handle any tank in that range.

Pump Specifications

• Target Flow Rate: 15,000 to 25,000 Litres per Hour (L/h) or 250 to 416 Litres per minute (L/min).
• Pump Type: A standard, non-submersible centrifugal surface pump or a high-flow peripheral pump.
• Materials: Ensure the pump wet-end (impeller and casing) is made of a chemical-resistant plastic or high-grade stainless steel (316 SS), depending on the chemical you are dosing.
• Plumbing Size: Use a minimum of 40 mm to 50 mm (1.5" to 2") pipe diameters for the suction and return loop lines to prevent choking the pump's flow rate.

5.  Programming and Calibration

Once powered up, the screen will display its software version before reading live pH values.

• Calibration: Press the CAL button and submerge the probe into a pH 7 buffer solution to adjust the "Zero" configuration. Rinse with clean water and repeat using a pH 4 or pH 9 solution depending on your target setpoint.
• Dosing Logic: Configure your setpoint inside the menu. If you are dosing acid to reduce high raw water pH, set the logic to Acid Mode (doses when pH rises above setpoint). If dosing alkali, set it to Base Mode (doses when pH drops below setpoint).

Soda Ash (Sodium Carbonate) Dilution Guidelines

• Target Concentration: 10% solution (approx. 10 kg of soda ash powder per 100 litres of water).
• Preparation Steps:

1. Fill the 100-litre tank roughly half-full with warm or ambient softened water.
2. Slowly add 10 kg of food-grade or technical-grade soda ash powder while mixing continuously to prevent caking at the bottom.
3. Top up the remaining volume with water to reach the 100-litre mark and stir until fully dissolved.

• Application Note: Soda ash is safer to handle and raises both pH and total alkalinity, making it ideal for low-alkalinity water.

Caustic Soda (Sodium Hydroxide) dilution Guidelines

• Target Concentration: 5% to 10% liquid solution (lower concentrations prevent over-dosing on small systems; use 5 kg of solid pearls or equivalent liquid volume for a 5% mix per 100 L).
• Preparation Steps:

1. Fill the clean 100-litre tank about 70% full with pure or softened water. Always add chemical to water, never water to the chemical.
2. Slowly add 5 kg of solid caustic soda (or calculate based on liquid stock purity, e.g., using a 50% stock solution). Caution: This causes a strong exothermic (heat-releasing) reaction.
3. Allow the solution to cool, then add remaining water to reach 100 litres and mix thoroughly.

• Application Note: Caustic soda is roughly twice as effective as soda ash at raising pH, does not increase carbonate hardness, but is highly corrosive and requires strict PPE (face shield, rubber gloves, apron