What to do when your controller is Putting too Little or Too Much Chemicals

Issue 

Resolution 

Probe value inaccurate: If the probe is not accurately tracking with the water chemistry it can cause the body of water to overshoot. An example of this would be the chlorine probe reading 2ppm while the chlorine is actually testing at 5ppm 

Calibrate probe or follow probe troubleshooting procedures. 

Feed settings incorrect: Depending on the design of the pool or spa there can be a significant lag time between when the chemicals are injected and when they mix in with the water. 

Enable time cycling or proportional feed

Hand dosed chemicals: A common source of overfeeds may actually occur from someone hand dosing a chemical and not noting it. Or hand dosing a chemical that may adversely affect values that it is not directly adjusting. An example of this would be sodium bicarbonate for alkalinity will also raise your pH. 

Note when chemicals have been added in manual readings or log book. Ensure chemicals are properly measured and dosed to limit impact on automation equipment by closing the flow chamber valves to allow time for the chemical to properly mix in the water.   

Flow Issues: If your system has poor flow or has a malfunctioning flow switch it can result in overfeeding chemicals. If the controller thinks it has flow whether thats because the flow switch is malfunctioning or some other outside factor it will feed chemicals. In order for the controller to accurately feed chemicals constant flow is required so that it can adjust feed pumps as the chemistry changes 

Test flow switch on at least a weekly basis to ensure that chemicals are interlocked when flow is lost. 

Issue 

Resolution 

Dosing Alarm: Most underfeed situations will display a dosing alarm when they occur. This could be for myriad reasons. Dosing alarms are a crucial fail safe that will help mitigate issues when failures occur. Sometimes however, the dosing alarm could be the cause of the underfeed. 

Raise dosing alarm timer if certain all chemical feed devices are working as they should be free of clogged lines and stocked with chemicals. Also ensure that probes are tracking accurately. 

Chemical Feeder: Oftentimes underfeeds are a result of some kind of malfunction with the chemical feed device. 

If using peristaltic pumps, such as Stenner pumps, always ensure they are operating free of clogs especially on chlorine lines. Additionally ensure that all fittings going into squeeze tubes are tight and that  the squeeze tube itself is undamaged. If using other feed devices investigate anything that could cause chemicals to not enter the body of water. On Cal-Hypo systems ensure solenoid valves are actuating, water is flowing and the venturi is functioning. 

Chemical Stocking: The most common cause of underfeed situations is simply running out of chemicals. 

Always check feed hoppers and chemical barrels to ensure that they are stocked and full. 

Incorrect feed settings: Sometime feed settings may be set too conservatively to adequately treat the body of water. 

Adjust feed settings by using on/off feed modes or make time cycling and proportional settings less conservative. Special feed modes are a great tool for preventing overfeeding chemistry but can cause you to not reach the desired setpoint if set too conservatively.  

Undersized feed equipment: Depending on a number of variables the feed equipment for your pool or spa may be too small to keep up with demand. 

Consult your Vivo Account representative to see if your equipment is sized correctly.