Calcium Reactor internal pH 9.08

[AlexandraDreadlocksPanda]

Hi all! I can’t figure this out. I don’t think it’s a data error, as I have cross referenced 2 x calibrated high spec Hanna lab grade pH probes with separate controllers, Hanna Checker Marine pH, Salifert pH, Hanna DKH checker and Salifert KH kit, data range is within the quoted error margins of the checkers & kits, so I can’t imagine everything is giving a consistent, coherently wrong reading…?
So, I’m starting up calcium reactor as Modern Reef dosing is getting ridiculously expensive on my system. Kit is:
•Ultrareef UCS160 Ca reactor
•Ecotech Versa feed pump
•CO2 Art pro regulator
•generic pH/Orp controller
•Hanna dual junction Lab grade probe (about £300 new - not junk!)
•coarse crushed coral skeleton media
•KZ Zeomag media

So I set up the reactor, let it run without CO2 for 48 hours to get completely degassed etc. Set flow rate as per reactor instructions, 30ml / minute and about 3 bubbles CO2 every 2 seconds. Now here’s where it gets insane. I paused the feed pump to try to get pH down in reactor, wouldn’t drop below about 7.8, solenoid keeping feeding CO2. Had to nip out for an hour and was amazed to see pH in reactor had risen massively, is now at 9.09 and is slowly rising (feed pump is running now, have switched off CO2), and effluent DKH is 49.4. Water in reactor above media is crystal clear.
I’m hoping someone with more of a chemistry brain can understand what’s going on here and advise, as I don’t think switching CO2 back on with a pH point of 6.8 is going to go well. I’ve kept reef for 20+ years, have had calcium reactors before on systems but have never seen one act like this!
@Randy Holmes-Farley any ideas?

 

[Randy Holmes-Farley]

That would be an error of some sort unless what you put into it is not calcium carbonate. There's no scenario where the pH rises way above normal tank pH inside a closed CaCO3/CO2 reactor.

 

[AlexandraDreadlocksPanda]

That would be an error of some sort unless what you put into it is not calcium carbonate. There's no scenario where the pH rises way above normal tank pH inside a closed CaCO3/CO2 reactor.

I’ve used this media in the past, same batch, sealed container. The only new and unknown is the KZ Zeomag media. I just can’t understand how I’m seeing these figures - I’ve swapped out the ph probes, rechecked their calibration, checked them in the sump, everything checks out and is confirmed by the Hanna colourimeter checkers etc. I honestly don’t know where to go with this now, I’m stumped.
Tempted to set up the Ca reactor just manually, tune the DKH and ignore the pH readings…. It just seems wild that so many different kits, probes, equipment are giving consistently incorrect readings when they all cross reference just about perfectly…

 

[Randy Holmes-Farley]

I’ve used this media in the past, same batch, sealed container. The only new and unknown is the KZ Zeomag media. I just can’t understand how I’m seeing these figures - I’ve swapped out the ph probes, rechecked their calibration, checked them in the sump, everything checks out and is confirmed by the Hanna colourimeter checkers etc. I honestly don’t know where to go with this now, I’m stumped.
Tempted to set up the Ca reactor just manually, tune the DKH and ignore the pH readings…. It just seems wild that so many different kits, probes, equipment are giving consistently incorrect readings when they all cross reference just about perfectly…

You certain you did not calibrate with pH 4 and 10 when the device expected pH 7 and 10 fluids, or some such thing? Or get the pH 7 and 10 backwards during calibration?

 

[AlexandraDreadlocksPanda]

You certain you did not calibrate with pH 4 and 10 when the device expected pH 7 and 10 fluids, or some such thing? Or get the pH 7 and 10 backwards during calibration?

Definitely not. There’s quite a few threads on here from the past couple of years, and comments on the product page at BRS that confirm this - with people seeing reactor pH between 8.5 and 9.5… You’d hypothesised on here previously that the Zeomag may have a fine very soluble carbonate component on it that initially spikes reactor pH. Everyone seems to find it normalises within 2 - 3 days. I’m glad other people have experienced this phenomena, you start to question your sanity when you cross reference so many things and triple check everything to no avail

 

[Randy Holmes-Farley]

Definitely not. There’s quite a few threads on here from the past couple of years, and comments on the product page at BRS that confirm this - with people seeing reactor pH between 8.5 and 9.5… You’d hypothesised on here previously that the Zeomag may have a fine very soluble carbonate component on it that initially spikes reactor pH. Everyone seems to find it normalises within 2 - 3 days. I’m glad other people have experienced this phenomena, you start to question your sanity when you cross reference so many things and triple check everything to no avail

OK, if that is true it must not be calcium carbonate that causes the issue,. Doesn't give me high confidence in the product.