Programming return pump and float switch

[john1979]

I'm trying to program a float switch to protect my return pump from running dry. How can I program it so that it doesn't cycle on and off as the water from the aquarium drains down then gets pumped back up over and over.

I would like to program something so that if the switch is triggered the pump just stays off (like a physical relay switch). I read pg. 94 of the Unofficial User's Guide, but I don't understand how that code works:

Fallback OFF
If FeedD Then ON
If Switch1 OPEN Then OFF

How does this code keep it from cycling back on when the water drains back into the sump? Won't the water from the aquarium close the switch, turning everything back on?

Any help would be appreciated!

John

[Ripperj]

You could use 2 switches, one higher than the other, or add a delay that either keeps the pump off for x minutes after the switch actuated, or keeps it on for x minutes longer after the switch changes state. You are trying to keep the pump from cycling on and off really fast correct?

[Ripperj]

I might have misread your original post, I would think that the system would have enough water so that the return pump could not run dry, all the water removed with the return pump should immediately flow back to the sump, so the level never changes??

[john1979]

Normally, the water level in my system is steady. However, I have a small space for my ATO water (only 1.5 gallons), so I need to replace it every day. If I forget, or if there's a lot of evaporation on a given day, my ATO reservoir could empty and the evaporation will continue, causing the water level in my return section of the sump to get too low.

Before I got my Apex, I used a float switch attached to a relay switch. If the float dropped because the water was too low, the relay switch activated and turned off the return pump. After I added some water, I would have to press on button on the relay switch to turn the pump back on. I would like to duplicate this using the Apex. I need to program a virtual relay switch.

[RussM]

See the last couple of posts in this thread: http://www.reefcentral.com/forums/showthread.php?t=2017188

You can employ the same technique.