APEX Automatic Water Change without DOS

[TheClark]

Hey all, just sharing in case someone is interested...

I used to run a noisy dual head peristaltic pump for water changes. The tubing went out so I decided to try something different.

Changed over to drain/refill method with APEX. It works well so far, although I have trust issues and only schedule them to run when I am here.

Caveat emptor, you have to know APEX pretty well and more importantly test out automation and observe! Don't go and hook this up right before a vacation or something silly like that

Requires:

APEX
ATO Float wired to apex
Optional - Sump High float wired to apex (emergency)
NSW Feed pump in apex outlet
SW Drain pump in same area as ATO floats and in apex outlet

That's it.

Here is the programming, highly leveraged from APEX forums

DRAIN_PUMP

Fallback OFF
Set OFF
# or whatever time you want to run it... Key is it has to run for at least two minutes due to Time command or you have to add a delay
If Time 16:22 to 16:23 Then ON


ATOSW_3_2

If Outlet SW_ATOLO5152 = OFF Then OFF
# This line turns it on, it will not turn off again unless one of the OFF conditions is met
# If you put this line first, the delay and the fact that the ATO does not go low right away
# can result in this outlet never turning on
If Outlet DRAIN_PUMP = ON Then ON
If Outlet SW_SumpHi_2 = ON Then OFF
If FeedA 000 Then OFF
If Power EB8_4 Off 000 Then OFF
If Condx5 > 36.0 Then OFF
# This line is tied to the time command in the drain pump
Defer 001:59 Then ON

Be careful not to create siphons. For example, the drain pump needs to pump up hill and have an air break or you will empty your sump.

Same deal on the NSW pump

 

[143MPCo]

Thx for share, hows it been working for you?

 

[TheClark]

No problem, so much good stuff in the forums, glad to share back.

It works really well. I still make sure to be in the room when it runs just because of the risks. However, after a levamisole mishap, I changed out 700 gallons or so with this method a few gallons at a time from the comfort of a desk chair

There are some built in safety measures worth mentioning:

1) The drain pump intake is situated high enough in the return chamber such that it cannot drain the water too low and run the return pump dry if the outlet sticks on (would rather lose 15 dollar pump than return)
2) There is a third float, 'sump low' for extra safety.
3) You can put a float on your NSW container and postpone water changes if that float triggers. Our container is 425 gallons though so it isn't really necessary, just a check once a week or so...

I borrowed this program from the apex guru himself aquamaniac here:

https://forum.neptunesystems.com/showthread.php?35-Sample-Program-Automatic-Water-Change

The key change for me was swapping the two lines in the NSW pump code. Otherwise, sometimes the NSW pump would not turn on if timing was off.