Apex Programming - AutoWaterChange with multiple ATK Pumps

[Beanju]

Hello I have tried to add as many detail as possible in the Tank System image.

Couple of users stories of what's going on :
I have a small RODI reservoir above my sump inside my aquarium cabinet, when the water decrease in the sump ( ATK_LO Sensor ),the pump runs and refill till the ATK_LO close.
I have my mixing station in the garage with an ATK pump in the rodi reservervoire, when the sensor RO_LO Open in the rodi reservoir located inside the aquarium cabinet above the sump open, the pump run to refill and stop when RO_LO close or GRO_LO close
This takes care of refiling my RODI and works without any issues.

I added an ATK pump ( FMMPumpSump) inside my Sump and an other sensor ( SumpLo) , which open when I remove 2 gallons of water in the system.

I am struggling with programming for a water change. What I would love to do
flip the switch AutoWC and then
- ATK_P ( atk pump in the rodi reservoir above the pump does not start )
- FMMPumpSump starts and run until SumpLo is open ( I remove 2 gallons of water )
- PumpSaltWc starts ( a pump located inside my salt water reservoir ) and run until ATK_LO is close
- If too much water was added ( ATK_HI is closed ) , run the FMMPumpSump until ATK_HI is open
- AutoWC goes to Off
- re activate ATK_P so next time ATK_LO open it refill with rodi

I am getting a headache haha
Help appreciated

 

[rygh]

Programming is a problem, yes.
A possible solution is to create a time based state machine.
From 8:00 to 9:45, your RODI fills until SumpHi is triggered
From 9:00 to 9:15, you turn water-out pump on, unless SumpLo is triggered.
From 9:30 to 9:45, you turn water-in pump on, unless SumpHi is triggered.

Warning:
Level sensors are not particularly accurate. The water-in and water-out may not match well, causing salinity drift.
Most people use matched peristaltic pumps. Just run both at the same time, for a few minutes every couple of hours.

 

[vissen319]

Maybe try ultrasonic or optical level sensors..Not sure whether there is one compatible with apex or perhaps need to wire out something.

 

[iani]

Optical sensors seem very dangerous. My optical sensors on my atk need to cleaned with some frequency to keep them from messing up. Does anyone know how accurate the pressure sensors avast sells are?

 

[vissen319]

Yes, optical sensors are very sensitive but I think one of his problem is that he only has a high level. So there is no failsafe.

Probably best to have a HH setpoint with a control switch as a failsafe too.

 

[Beanju]

I have float valves too, so mechanically close in case something go south.
The “only” risk is the pump in the sump removing water non stop and empty the sump.

 

[rygh]

It is also very important to have a sensor in the salt water reservoir.
You WILL forget to mix salt water at some point, and it will go empty.
So you need a failsafe to make sure it does not exchange tank water with air.

 

[iani]

I would possibly put the pump in the sump on a timer with the sensor being the back up. Have the pump turn on for a set period of time equal to what you want to drain. As rygh said having a sensor in the salt water make up tank is crucial as well. I'm really sad reef genesis went out of business as their AWC product is rock solid for me so far. With their system there is really no way for salinity to drift.