elwaine
The mad reefer
I seem to have an interesting occurrence ââ"šÂ¬Ã¢â‚¬Å“ not a problem really ââ"šÂ¬Ã¢â‚¬Å“ and I know that it is not a pH monitor calibration error as I recently calibrated my Pinpoint pH monitor.
Just before the actinic lights turn on, over my main tank, all parameters are normal:
pH 7.95 + or - 0.03
alkalinity 2.75 ââ"šÂ¬Ã¢â‚¬Å“ 3.00 meq/l
calcium 380 ââ"šÂ¬Ã¢â‚¬Å“ 400
sp.gr 1.024
NO3 0.0 ââ"šÂ¬Ã¢â‚¬Å“ 0.2
PO4 0
Temp 80 ââ"šÂ¬Ã¢â‚¬Å“ 81 degrees F
but after the actinics come on, over my 37 g reef tank, the pH drops to 7.85 + or - .03
Typical repeat chemistry values, 5 hrs after the MH lamp turns on, are the same as above but with a pH in the range of 8.02 + or ââ"šÂ¬Ã¢â‚¬Å“ 0.03 Just before the MH switches off, after an 8 hour photo period, the pH will max out at around 8.05. The actinics stay on an additional 3 hrs, during which time there is a slow drop in pH back to about 8.0
My question is, why does the pH drop after the actinics come on? As I understand it, the pH should rise when the lights come on. I ought to note that the pH is stabile for about two hours prior to the time the actinics come on. Perhaps I am seeing utilization of alkalinity and calcium - during the initial phase of the light cycle ââ"šÂ¬Ã¢â‚¬Å“ at a rate that exceeds CO2 production from respiration.
Since the pH and the Alkalinity are at the lower range of normal, maybe I should up the dose of overnight of additives, or add more limewater to my top off tank. Any comments about that?
I do not have a calcium reactor. I dose two part balanced additive solutions (Hardness Plus and Alkalinity Plus from NatuReef) overnightââ"šÂ¬Ã‚¦ but the last dose is 3 hours before the actinics turn on. I add kalkwasser to the RO water in my top-off tank, but it is a rather dilute solution and I do not know what the concentration is, nor do I know how much of that solution is added to my main tank as the evaporation rate varies daily. I use both activated carbon and RowaPhos. My salt mix is from Oceanic, and I do 5% water changes every 2 weeks. The weather in SW Florida is ideal this time of year and so the sliders (glass doors) are always wide open and I doubt there is a measurable difference between the CO2 in air inside and outside of the houseââ"šÂ¬Ã‚¦ and the reef aquarium is only 2 feet from a slider. Finally, the lights over my 10 g sump/refugium are on except between the hours of midnight and 3 AM
TIA... Larry
Just before the actinic lights turn on, over my main tank, all parameters are normal:
pH 7.95 + or - 0.03
alkalinity 2.75 ââ"šÂ¬Ã¢â‚¬Å“ 3.00 meq/l
calcium 380 ââ"šÂ¬Ã¢â‚¬Å“ 400
sp.gr 1.024
NO3 0.0 ââ"šÂ¬Ã¢â‚¬Å“ 0.2
PO4 0
Temp 80 ââ"šÂ¬Ã¢â‚¬Å“ 81 degrees F
but after the actinics come on, over my 37 g reef tank, the pH drops to 7.85 + or - .03
Typical repeat chemistry values, 5 hrs after the MH lamp turns on, are the same as above but with a pH in the range of 8.02 + or ââ"šÂ¬Ã¢â‚¬Å“ 0.03 Just before the MH switches off, after an 8 hour photo period, the pH will max out at around 8.05. The actinics stay on an additional 3 hrs, during which time there is a slow drop in pH back to about 8.0
![53023ph.jpg](/proxy.php?image=http%3A%2F%2Freefcentral.com%2Fgallery%2Fdata%2F500%2F53023ph.jpg&hash=87c161bd0aca7ea0e57dca8dba90060c)
My question is, why does the pH drop after the actinics come on? As I understand it, the pH should rise when the lights come on. I ought to note that the pH is stabile for about two hours prior to the time the actinics come on. Perhaps I am seeing utilization of alkalinity and calcium - during the initial phase of the light cycle ââ"šÂ¬Ã¢â‚¬Å“ at a rate that exceeds CO2 production from respiration.
Since the pH and the Alkalinity are at the lower range of normal, maybe I should up the dose of overnight of additives, or add more limewater to my top off tank. Any comments about that?
I do not have a calcium reactor. I dose two part balanced additive solutions (Hardness Plus and Alkalinity Plus from NatuReef) overnightââ"šÂ¬Ã‚¦ but the last dose is 3 hours before the actinics turn on. I add kalkwasser to the RO water in my top-off tank, but it is a rather dilute solution and I do not know what the concentration is, nor do I know how much of that solution is added to my main tank as the evaporation rate varies daily. I use both activated carbon and RowaPhos. My salt mix is from Oceanic, and I do 5% water changes every 2 weeks. The weather in SW Florida is ideal this time of year and so the sliders (glass doors) are always wide open and I doubt there is a measurable difference between the CO2 in air inside and outside of the houseââ"šÂ¬Ã‚¦ and the reef aquarium is only 2 feet from a slider. Finally, the lights over my 10 g sump/refugium are on except between the hours of midnight and 3 AM
TIA... Larry