works on a light, but not a pump?

[van headche]

I have an aquacontroller jr, dc8, and a pH probe that I am trying to use to shut off my kalkreactor when the Ph is 8.3 or higher.

I am using a tom aquatics aqualifter to push water through the system. The problem i am having is that when i reach the desired pH, the pump will not shut off. Why is there still a current? When I put a test light in the same plug on the dc8, it shuts off fine when the pH reaches 8.3 every time.
Is it the pump that is not allowing the aquacontroller to update the status of the plug in the dc8?
Another thing, if the pH is above 8.3 and the pump is still running(when it should not be) and i unplug it and plug it back in, it remains off until the pH drops below 8.3 as it should.

Is this an issue or am i doing something wrong?

Thanks

[Cheekymonkey]

If you have an old DC8 then you are in a tuff spot, but if you have a new DC8 put it on one of the relays (Plugs 4 and 8)

[dougchambers]

The problem has to do with the DAC in the DC8. The Aqualifer pumps are a know issue with the DC8s because they don't draw enough current for the Direct Connect module to sense a load.

You have two options;

1. Install a small light bulb or other device on the same outlet as your Aqualifter to create more load.

2. Buy the DC4 or DC4HD. They use relays instead of DACs so they don't have to see a load.

-Doug

[van headche]

Thanks for the quick replies!
I will try it on 4 or 8 first. I don't know if it is a new one, but i got it from marinedepot within the past 6 months.

[Cheekymonkey]

should be a new one then, check the serial # on it....

[van headche]

Yep, that was it. Thanks again.

[Cheekymonkey]

Glad I can help i'm a AC nub still

[van headche]

Well, it's been a week and my pH has been very stable. When i first set this equiptment up, i had no idea it was running 24/7. It now is about 8.33 in the day and drops to about 8.23 at night. It used to go from 8.28 down to 8.05 or lower.

Thanks again!
Greg