[trilinearmipmap]

OK this is the idea I was thinking of trying out to see if it works.

For fine-tuning my calcium reactor I try to check my Ca and Alk once every week or two when I get around to it. Obviously weekly would be better but it is easy to slack off when there are so many other things to get done.

The basis of this idea is that the carbonate/bicarbonate buffer system is the main determinant of pH in a reef tank, and the three variables of pH, ppm CO2, and Alkalinity are related by a mathematical equation. The idea is to set up a constant monitoring of Alk as follows:

1. Get a small container such as a 1 Litre yogurt container and put it in my sump, feed water into it at a slow rate teed off from my return line through a small 1/4" hose such as 10 mL per minute or so. The water would gradually fill the 1 Litre container and then spill back into the sump.

2. Put a Maxijet with venturi into the 1 Litre container and leave it running. The Maxijet is to aerate the water in the container so its CO2 content equalizes with the CO2 content of the air in the room.

3. Put a pH probe in the container and monitor the pH constantly.

4. Every week when doing the Salifert Alk test, write down the pH of the aerated tank water and write down the measured Alk value. After some time see if there is a good correlation between pH and Alk, there should be a close correlation unless the room CO2 concentration varies markedly, or the pH probe goes out of calibration.

5. Once there is enough data to show a good correlation between pH and Alk then I could use the pH probe as an "early warning system" to see if the Alk is getting out of line, and hopefully if the pH is in bounds then it would reduce the necessity to do regular Alk and Ca tests (as Ca should follow Alk when you are doing any form of balanced dosing).

I am just wondering if anyone has tried this already or if there is any reason why it wouldn't work.