Ph & ORP probes in return line?

spreston · 03/05/2008, 07:19 PM

I just installed both probes in the return line and just like that the ph reading dropped from 8.09 to 7.93. As well, the ORP reading dropped from 325 to 290, although having this out of the water for a minute I figure it will come around. However, I am baffled why the ph would drop. Maybe the probes are receiving to much flow? I installed them to where I believe the bottom of the probe is flush with the bottom of the "T". The probes are about 14" apart, ph first then ORP. Any ideas, or wait unitl tomorrow after they have settled in?

spreston · 03/05/2008, 07:22 PM

I failed to mention that I re-calibrated the ph probe about 20 minutes before installing. However, the 8.09 was the reading after calibration for the few minutes it was in the sump.

Billybeau1 · 03/06/2008, 12:03 AM

I do not know how accurate those probes are in a high flow area. Many people put them in their sumps. I have mine in the main display but well away from the return flow of water, probably in the calmest part of the tank.

Randy Holmes-Farley · 03/06/2008, 05:52 AM

Are you sure they are fully submerged?

Where were they before?

spreston · 03/06/2008, 08:14 AM

Quote:

Originally posted by Randy Holmes-Farley
Are you sure they are fully submerged?

Where were they before?

They were in the sump before. The ORP is back normal & the ph did not drop to much overnight. I am going to take it out and clean it tonight. Might be some glue at the bottom of the "T" or something may have gotten on the probe tip.

Randy Holmes-Farley · 03/06/2008, 01:23 PM

OK, let us know what happens.

03/05/2008, 07:19 PM	#1
spreston Registered Member Join Date: Jul 2007 Location: Edmond, OK Posts: 373	Ph & ORP probes in return line? I just installed both probes in the return line and just like that the ph reading dropped from 8.09 to 7.93. As well, the ORP reading dropped from 325 to 290, although having this out of the water for a minute I figure it will come around. However, I am baffled why the ph would drop. Maybe the probes are receiving to much flow? I installed them to where I believe the bottom of the probe is flush with the bottom of the "T". The probes are about 14" apart, ph first then ORP. Any ideas, or wait unitl tomorrow after they have settled in?

03/06/2008, 05:52 AM	#4
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	Are you sure they are fully submerged? Where were they before? __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

03/06/2008, 01:23 PM	#6
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	OK, let us know what happens. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

03/05/2008, 07:22 PM	#2
spreston Registered Member Join Date: Jul 2007 Location: Edmond, OK Posts: 373	I failed to mention that I re-calibrated the ph probe about 20 minutes before installing. However, the 8.09 was the reading after calibration for the few minutes it was in the sump.

03/06/2008, 12:03 AM	#3
Billybeau1 Registered Member Join Date: Jul 2005 Location: Dyer, Indiana Posts: 12,010	I do not know how accurate those probes are in a high flow area. Many people put them in their sumps. I have mine in the main display but well away from the return flow of water, probably in the calmest part of the tank.