The KH Manager has a built-in magnetic stirrer to stir the contents of the beaker during the flushing cycles before a test and to mix the sample during the test. If the stirrer is not operating correctly you will get false or erratic KH and pH test results.

As the KH Manager goes through its test procedure you should be able to observe the stirrer bead go through cycles of spinning and stopping. When visually checking the operation of the bead make sure that the pH probe and drain tube are positioned correctly so that they will not interfere with the rotation of the stirrer.

During the flush cycles the bead is set to spin automatically at a high speed and then will slow during a test to the user set speed. Throughout the test it is important that the sample is well mixed, but you do not want the stirrer to run at a speed that will drag air bubbles into the sample. These bubbles could cause inaccurate readings from the pH probe which will intern cause incorrect KH test results. We would recommend that a setting of 15%-20% is enough when using the standard glass beaker provided with the KH Manager and a 50ml test sample volume (this is the factory pre-set volume).

In extreme cases if the stirrer is set to run at a higher than needed speed it could cause the bead to jump and damage the pH probe.  

Setting the speed of the magnetic stirrer.

1. Log in to the Kamoer Remote app and tap on the tile icon for your KH Manager
2. Choose ‘Settings’ in the bottom right corner followed by Maintain / Runing Pumps.
3. Near the bottom of the page is the ‘Stirring Pump’ option.
4. To adjust the speed of the stirrer move the slider left or right, the current power setting is shown on the right next to the slider bar.
5. When the power setting has been done tap on the ‘Run’ button in the ‘Stirring Pump’ tile to check the speed, to stop the stirrer tap on the run button again which should now be displaying ‘stop’.

If the bead skips or does not rotate properly it is possible that it is touching the end of the pH probe, touching the drain tube or the speed is set to high. Check that nothing is obstructing the bead, if the bead is free to move reduce the power setting as above. A speed of around 15-20% is normally ideal. When spinning properly it is normal to see a whirlpool motion in the test beaker but there should not be air being drawn into the sample from the surface, if air bubbles are being drawn down into the test sample reduce the speed of the stirrer.