Some of you may have seen a planted tank table I have passed around that shows the relationship between CO2, DKH and PH. Personally this table has really helped me understand my system better hence my attempts to share it. By having my DKH supplement on a doser, skimmer set schedule with outdoor air (I assume its more stable with co2 concentration then indoor air) and a PH monitor I developed insights over repeat observations. When looking at the tank I have been able to correlate increased DKH consumption (and hence lower total tank DKH) and my PH being low together almost as a simple alert. My best guess is that because I have become in tune with my tanks PH range on a normal day and if the DKH is low you can see it in the PH. Anyhow I bring this up because I found it both fascinating and important to realize you can gain an understanding of your DKH based on PH.
@Randy Holmes-Farley let me know that because the table I was sharing was for a freshwater planted tank that it was incorrect. To try and put correct information out there I used the NOAA CO2SYS application to input the proper DKH (alkalinity) and PH along with other constants such as temperature and salinity. Using Python I put together a simple script (shared below) that uses CO2SYS and loops over a set of values for PH and DKH to calculate the CO2.
This application is well beyond my knowledge and hopfuly someone out there can help sanity check the values in the table! If you see something wrong please let me know.
Constants Used
Table for Marine Tanks generated with CO2SYS
CO2SYS @ NOAA
CO2SYS Python Library
Script to generate table (work in progress, very MVP right now)
pH And The Reef Aquarium
@Randy Holmes-Farley let me know that because the table I was sharing was for a freshwater planted tank that it was incorrect. To try and put correct information out there I used the NOAA CO2SYS application to input the proper DKH (alkalinity) and PH along with other constants such as temperature and salinity. Using Python I put together a simple script (shared below) that uses CO2SYS and loops over a set of values for PH and DKH to calculate the CO2.
This application is well beyond my knowledge and hopfuly someone out there can help sanity check the values in the table! If you see something wrong please let me know.
Constants Used
- Salinity 35 PPT
- Temperature 25C
- Silicate 50 umol/kg
- Phosphate 4 umol/kg
- PH Scale (2 Tables, see tabs)
- NBS/NIST
- What Hobby Probes use and what most of us refer to as PH
- "Free" i.e. pH=−log10[H+]pH=−log10[H+].
- NBS/NIST
- Read Randy's Article on PH
- Perform "The Aeration Test" found here as independent verification of high CO2
- Gather inputs from your tank
- DKH and PH
- Identify Intersection on table
- PH across the top and DKH on far left side. The intersecting values are the tanks current CO2 ppm
- Internet Results (coming soon)
Table for Marine Tanks generated with CO2SYS
CO2SYS @ NOAA
OCADS - Program Developed for CO<sub>2</sub> System Calculations
www.ncei.noaa.gov
CO2SYS Python Library
Script to generate table (work in progress, very MVP right now)
GitHub - josephxsxn/marine_co2: Marine Aquarium CO2SYS Calculations
Marine Aquarium CO2SYS Calculations. Contribute to josephxsxn/marine_co2 development by creating an account on GitHub.
github.com
pH And The Reef Aquarium
pH And The Reef Aquarium
For many aquarists, pH is not something that they have much experience with aside from their aquarium. For many, pH is almost a black box measurement: something to be considered, but whose physical meaning makes little sense to them. This...
www.reef2reef.com
Last edited: