Continuous Water Change

[Rob F]

Hi Mike, for a while now I've been wanting to add a auto water change system, quite a few have asked about that but not sure if anyone is doing it.

For continuous or steps I would use custom rules which are flexible, the dosing pumps have lots of issues as you pointed out.

This is a simple setup and assumes the drain for old tank water is unlimited, if not a custom rule can be added for that.

Setup a pump to drain (call it DC1) and a pump to fill (DC2) using 2 DC accessory ports, one for each pump for better control as lift height etc can change how much is pumped per min using the same pump.

Then setup a float switch at the top of tank (Sensor1) and button of reservoir (Sensor2) both on different sensor ports.

Then for the custom rules you would create 4 of them.

• Select "Sensor1" and set "if open" and have it turn on "DC2"
  
• Select "Sensor1" and set "if closed" and have it turn off "DC2"
  
• Select "Sensor2" and set "if open" and have it turn on "DC1"
  
• Select "Sensor2" and set "if closed" and have it turn off "DC1" and "DC2"
  
• Select "sensor3" and set "if closed" and only select "send email"  (optional email alert for low level in reservoir)
  

With this the 2 pumps would always run unless the float in tank (sensor1) closed as in tank has too much water it would shut off pump in reservoir (DC2) and continue to pump water out of tank until "sensor1" open again and at that point "DC2" would start up again adding more water. This would continue until the reservoir was empty, and the 3rd rule would shut DC1 and DC2 off and send you an email letting you know reservoir is low. You could add a 2nd float switch in reservoir to "sensor3" port and maybe set that 3/4 in reservoir, when it hits that point it would email you letting you know the reservoir is almost empty. The rule wouldn't do anything but email you. You could also add extra float switches as backups. A cheat for backups so you don't use extra sensor ports is having multiple float switches on the same port doing the same thing and set floats side by side.

There's no limit what you can do, you could also setup switches, pumps and valves to keep the reservoir full and probably even automate the mixing of reservoir. 

Actually there is a limit today because only so many ports, this simple setup uses 2-3 sensor ports and there's only 5. With the addons I'm working on I'll probably add up to 21 sensors and a whole lot of DC accessory ports. I'm also going to add more options in the custom rules so yeah lots of improvements to come but this should get you going today.

EDIT:

You can adjust the flow rate of the pumps by making a small change in the code, I'll be adding this to the GUI when I upgrade the custom rules.