Often I see posts about PH issues and trying to diagnose the root cause. More often than not, the suggestion is that high indoor CO2 levels are to blame for the low PH. I recently added a CO2 meter to my fishroom to provide feedback on some adjustments I had made. In the past, these meters were expensive and not that common, but now plenty of meters are available that use NDIR sensors and are a worthwhile addition to a reef hobbyists arsenal. Just knowing what the indoor CO2 level is helps to confirm or rule out that high indoor CO2 levels are the cause of low tank PH.
At my previous house I was faced with low PH. I read up and followed the advice on how to diagnose and adjust for it. I added an external skimmer line, and that helped a bit, and then I added a HRV with the fresh air exhaust pumped directly into the fishroom. That helped a lot. So when I moved a couple years ago, and as I was replacing all the HVAC equipment in the new house, I was certain to include a large capable HRV. Based on how useful the HRV was, and the fact that I had to have it operating pretty much 100% of the time to get the most benefit for the tank, I shelled out for models with ECM motors for the HRV and furnace to keep monthly hydro costs down.
My frag tank is running at about 7.95 without Kalk and 8.1 with. Not bad, but not the 8.2 and 8.3 that my old tank used to run at. So I decided to turn my HRV to Max ventilation rather than the "Smart" mode that allowed it to choose the duty cycle of the air exchange. This did not seem to have a noticeable effect on the PH of the tank. This fact got me to wondering if the new HRV was providing the same level of ventilation as the old system. Since I was dealing with finished ceilings, the new HRV was plumbed into the ducts in the utility room only and not venting directly into the fishroom like before. That is what gave me the idea of adding a CO2 monitor.
I could measure the indoor air quality and see if the HRV was keeping the CO2 level low, or if the Max setting was effective compared to the smart mode.
I ordered a cheap desktop CO2 meter and installed it a couple of days ago. The morning after, I went down and had a look at the reading. 430 ppm. So that tells me that the HRV is doing its job and keeping CO2 at pretty much outdoor levels. When my 2 dogs and myself wake up and are in the basement in the morning, the meter reading goes up to ~450 ppm. The meter seems to be pretty sensitive to changes in the local CO2 production. The manufacturer shows an accuracy of +/-30 ppm, so for my purposes, quite acceptable.
As for my lower than expected PH? A post by Randy from a few days ago has provided a clue as to the cause. I have a sulfur denitrification reactor inline with some of my filtration, and have noticed the lower than expected PH and Calcium getting out of balance with Alk, both of which are symptoms of using sulfur denitrification.
Anyway just wanted to post about a new tool in the reef hobbyists arsenal.
Dennis
At my previous house I was faced with low PH. I read up and followed the advice on how to diagnose and adjust for it. I added an external skimmer line, and that helped a bit, and then I added a HRV with the fresh air exhaust pumped directly into the fishroom. That helped a lot. So when I moved a couple years ago, and as I was replacing all the HVAC equipment in the new house, I was certain to include a large capable HRV. Based on how useful the HRV was, and the fact that I had to have it operating pretty much 100% of the time to get the most benefit for the tank, I shelled out for models with ECM motors for the HRV and furnace to keep monthly hydro costs down.
My frag tank is running at about 7.95 without Kalk and 8.1 with. Not bad, but not the 8.2 and 8.3 that my old tank used to run at. So I decided to turn my HRV to Max ventilation rather than the "Smart" mode that allowed it to choose the duty cycle of the air exchange. This did not seem to have a noticeable effect on the PH of the tank. This fact got me to wondering if the new HRV was providing the same level of ventilation as the old system. Since I was dealing with finished ceilings, the new HRV was plumbed into the ducts in the utility room only and not venting directly into the fishroom like before. That is what gave me the idea of adding a CO2 monitor.
I could measure the indoor air quality and see if the HRV was keeping the CO2 level low, or if the Max setting was effective compared to the smart mode.
I ordered a cheap desktop CO2 meter and installed it a couple of days ago. The morning after, I went down and had a look at the reading. 430 ppm. So that tells me that the HRV is doing its job and keeping CO2 at pretty much outdoor levels. When my 2 dogs and myself wake up and are in the basement in the morning, the meter reading goes up to ~450 ppm. The meter seems to be pretty sensitive to changes in the local CO2 production. The manufacturer shows an accuracy of +/-30 ppm, so for my purposes, quite acceptable.
As for my lower than expected PH? A post by Randy from a few days ago has provided a clue as to the cause. I have a sulfur denitrification reactor inline with some of my filtration, and have noticed the lower than expected PH and Calcium getting out of balance with Alk, both of which are symptoms of using sulfur denitrification.
Anyway just wanted to post about a new tool in the reef hobbyists arsenal.
Dennis
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