Ph Controller Issue - General Aquarium Plants Discussions

imatrout · 06-11-2006, 08:57 PM

I have heard that RO/DI water can play havoc with Ph Controllers. I recently switched over to RO/DI water. My Milwaukee SMS 122 (WHICH IS BRAND NEW compliments of a great support warranty at Milwaukee), is having diplaying a waivering Ph that causes the alarm and relay trip back an forth every second to two seconds. Has anybody ever heard of this and if so, what was the issue?

Thanks!

Cavan Allen · 06-11-2006, 09:23 PM

What's your KH? I can't see why RO would cause it to do that if you reconstituted it and it's in the recommended ranges.

imatrout · 06-11-2006, 09:45 PM

Cavan. KH is 4.0 I have not reconstituted the water, I use 1/3 - 1/4 hard tap water. I wonder if I should skip the DI process.....

**IUnknown** · 06-12-2006, 07:43 AM

Sounds like the probe needs replacing. They sent you a new controller, but is the probe new?

Quote:

To test your PH probe do the following test:

A simple test can be performed using Windex glass cleaner with ammonia and any type of soft drink The procedure is as follows: Turn your meter or tester on and place the probe in a soft drink which is acidic and the reading will be below 3.0 then go to the Windex with ammonia which is alkaline. Your display should move very quickly up the scale to above 10.0 If the probe slowly moves up the scale then it is time to consider replacing it.

bergzy · 06-12-2006, 10:25 PM

with a kh of 4...that means you can run at pH of 6.7 (bare bottom value) and have about 24 ppm co2 but...

when your lights go off and your plants consume o2...your ph will drop due to a somewhat low kh value...thus the fluctuations you see...

i run kh at 6 and have my ph controller set at 6.85 and see a 0.2 pH fluctuation when the lights are out. not the greatest fluctuation but at least my discus are doing okay!