Roger..
I can't leave well enough alone.. Dosing kalk through an auto-top-off, like the osmolator, can be kind of tricky in some situations, I don't really think I even need to explain here..
So here is what I am proposing.
Grabbed a pH controller I had around, grabbed a 120v relay from the shop with a NC and NO connection. When the relay is off, obviously, one connection is on, and one is off, when tripped on, they reverse. These two connections take the +9vdc from the osmolator and split them to two osmolator pumps, the grounds are shared and return back to the osmolator. The controller is set to energize the relay under the setpoint (say 8.1 for example). When the relay is energized, the pump connected to that output will pump water through a Nielsen reactor. Should the pH go over the setpoint (to 8.2), the controller will turn off the relay, and the second osmolator will pump RO water from the reservoir without going through the Kalk reactor.
Two benefits of this, should something go wrong with the top off and pH spike, the amount of kalk added will only bring the pH to 8.2 before switching to the RO feed. At that point the standard osmolator time or float overflow would catch it. Second, the pH will remain closer to the setpoint over the course of the day, during the high pH hours, top off will be RO, low pH top off will be Kalk. This will serve to minimize the daily pH swing. In this case, Kalk is used only for pH control to offset the pH caused by a calcium reactor or high indoor CO2, not for calcium and alkalinity addition.
So what is the word from the Tunze camp on doing something like this? I can't really see any issues switching the output pumps with a relay that would cause more wear and tear on the pumps or osmolator itself. I played around with the idea of using a solenoid to switch the pump output between the nielsen and just a straight RO feed, then I realized a second osmolator pump and relay would be much cheaper than the proper non-metalic 3-port solenoid would be.
jb
I can't leave well enough alone.. Dosing kalk through an auto-top-off, like the osmolator, can be kind of tricky in some situations, I don't really think I even need to explain here..
So here is what I am proposing.
Grabbed a pH controller I had around, grabbed a 120v relay from the shop with a NC and NO connection. When the relay is off, obviously, one connection is on, and one is off, when tripped on, they reverse. These two connections take the +9vdc from the osmolator and split them to two osmolator pumps, the grounds are shared and return back to the osmolator. The controller is set to energize the relay under the setpoint (say 8.1 for example). When the relay is energized, the pump connected to that output will pump water through a Nielsen reactor. Should the pH go over the setpoint (to 8.2), the controller will turn off the relay, and the second osmolator will pump RO water from the reservoir without going through the Kalk reactor.
Two benefits of this, should something go wrong with the top off and pH spike, the amount of kalk added will only bring the pH to 8.2 before switching to the RO feed. At that point the standard osmolator time or float overflow would catch it. Second, the pH will remain closer to the setpoint over the course of the day, during the high pH hours, top off will be RO, low pH top off will be Kalk. This will serve to minimize the daily pH swing. In this case, Kalk is used only for pH control to offset the pH caused by a calcium reactor or high indoor CO2, not for calcium and alkalinity addition.
So what is the word from the Tunze camp on doing something like this? I can't really see any issues switching the output pumps with a relay that would cause more wear and tear on the pumps or osmolator itself. I played around with the idea of using a solenoid to switch the pump output between the nielsen and just a straight RO feed, then I realized a second osmolator pump and relay would be much cheaper than the proper non-metalic 3-port solenoid would be.
jb
