The AutoPilot Total Control System promises to automatically regulate both chlorine and PH, eliminating all of the daily chores except cleaning out the skimmer basket. This is the only unit sold in the consumer market that includes these features. After spending nearly a whole season with an AutoPilot Total Control system I thought I would share my experiences.
The Total Control System consists of a digital control unit very similar to their Digital model, a manifold and cell ***embly identical to their other units, an acid tank with a peristaltic pump to inject acid into the pool, and a pool chemistry controller which includes Oxidation Reduction Potential (ORP) and PH sensors. There is also an optional auxiliary relay kit if you want the Total Control System to control your pump.
The Total Control System is substantially more expensive than the regular Pool Pilot Digital system, which uses the same SWG manifold/cell and a nearly identical digital control unit. A deep discount price for the Total Control system with auxiliary relay and SC-60 cell is around $2300, while the Pool Pilot Digital system with SC-60 cell goes for around $1000 from similar deep discount vendors. Neither price includes installation.
The Total Control system also has additional maintenance expenses. The PH and ORP sensors should be replaced every two years which costs close to $400. Over six years the Total Control system would cost on the order of $2100 more than the Digital system. That could be as much as three times the cost over six years (ignoring installation and electricity costs which should be similar).
Many of the features of the Total Control System are shared with the Pool Pilot Digital: both are salt water chlorine generators with a friendly alphanumeric display, automatic temperature compensation, a byp*** manifold ***embly, optional control of the pump, flexible salt levels, failure of the pump to prime protection, freeze protection, and support for pools of up to 50,000 gallons. The Total Control System adds automatic regulation of both FC and PH.
Installation went smoothly. Most of the install is the same as for any SWG; plumb the cell/manifold, then physically mount and wire electricity to the control unit. The Total Control System additionally required locating the acid tank/pump ***embly and wiring it into the control unit.
Then holes are drilled into the manifold and into a pipe on the intake side of the pump. The holes are used to connect hoses for water to feed the sensor ***embly and the acid feed line. Drilling the holes was easy. The quick clamp on hose connectors worked quite well and have not leaked at all. There wasn't quite as much tubing supplied as I would have liked, but I managed get everything hooked up with the tubing provided.
The manual is a mixed bag. The sections on installation were complete and readable, though they could have used another diagram or two. The descriptions of the various configuration options were lacking, however. The manual fails to make clear what several of the options are for and when you might want to use them. It was only after speaking with technical support that I discovered that the ORP Overfeed and PH Overfeed features are only intended for quite small pools and should be left disabled with any reasonable sized pool.
I had very mixed results with contacting technical support. My unit came with the wrong cell cable. A very friendly person at Auto Pilot had the correct cable in the mail to me the same day I first contacted them. Later when I was having problems with the ORP Overfeed and PH Overfeed settings I had two attempts to contact technical support go completely ignored.
I then switched to talking to Poolsean, an AutoPilot representative who is active on the forums, who was remarkably friendly and helpful. However he did not know the answers to all of my questions and so he tried to connect me to the technical support department. Again all contacts to technical support went unanswered, even through Poolsean was making the introductions.
Finally, after a couple of weeks of failing to get in touch with technical support, Poolsean got me in touch with a senior engineer who was finally able to answer my questions.
The automated PH control has proven to be highly effective. The system has held the PH between 7.45 and 7.52 quite reliably. The vast majority of the time the PH is between 7.47 and 7.5. Comparing the PH reading to a Taylor PH test over three months I have not detected any drift in the PH sensor reading.
Aeration from the hydrogen bubbles produced during chlorine generation raises PH. The system compensates, by adding muriatic acid using a peristaltic pump. The acid slowly lowers the total alkalinity. Two or three times a year I need to add more acid to the tank and put a couple of pounds of baking soda into the pool.
I find it entertaining that the Total Control system turns what is normally considered a disadvantage of a SWG, the tendency to increase PH, into an advantage. Since the cell will consistently raise the PH, the automation systems only needs to be able to lower the PH, to have complete control.
I was never able to get the ORP sensor to work in any useful way. As long as the system is producing chlorine, the ORP reading goes steadily down instead of up. The result is that the unit either never produces chlorine or always produces chlorine, depending on how the ORP goal is set. If I disable chlorine generation for a day, the ORP reading comes back to a more reasonable level.
AutoPilot believes that this behavior is caused by hydrogen gas, produced by the system, dissolving in the water. They suspect that something about my plumbing configuration causes the hydrogen to dissolve instead of bubbling to the surface. Dissolved hydrogen gas is known to lower ORP readings, and in my situation, this effect seems to be larger than the increase in ORP from added chlorine.
There is nothing particularly unusual about my plumbing. I have a single skimmer and a single return, both about 20 feet from the equipment pad connected with 1.5" pipe. I know that many other users of the Total Control System don't have this problem, but I have no way of knowing how widespread it really is.
There are various other known quirks with ORP sensors that can cause problems in specific situations. Non-chlorine shocks can sometimes cause high ORP readings, even when chlorine levels are quite low, leaving a pool unsanitized. CYA levels above 50 can reduce the change in ORP as chlorine increases to such small values that accurate automation is impossible. Readings vary from one ORP sensor to another and no reliable calibration standard exists. Therefore, ORP readings can only be taken as a relative indication and not as an absolute number.
Fortunately, the Total Control System can be configured to use the usual percentage-based chlorine production control, ignoring the ORP sensor, while still automatically regulating PH. With the automatic temperature compensation feature, and our fairly consistent bather load, the percentage based control works quite well. Still, it has been quite frustrating working slowly through all of the other possible causes for ORP reading errors for weeks, only to discover that there seems to be no hope of the unit ever working as designed.
The Total Control System fails to live up to its promise of automating both chlorine and PH levels. While we have been thrilled with the features shared with their Digital system and with the PH automation, the ORP controller completely failed to regulate chlorine levels. ORP sensors used for automation of public pools have a very mixed record. Even if you don't experience the particular problem we encountered, there are too many potential issues with ORP based automation. I do not recommend it for residential use.
The deficiencies in AutoPilot's technical support department also weigh more heavily against the Total Control System than their other products. It is easy to get support for their Digital system from various forums should you experience problems with their technical support. But knowledge about ORP automation is limited and there are many possible pitfalls. Without active support from AutoPilot, ORP based automation should be left to the dedicated hobbyists.
All that said, PH automation is a wonderful feature. It would be nice to see support for PH automation become available in a less expensive package. Percentage-based control over chlorine production is good enough for most situations. Adding PH automation to the Digital system, and leaving out the ORP feature, would be a much more appropriate combination for residential pools.