Don't run airstones when running CO2
, you are off gassing CO2
and creating un-stable CO2
levels which to some, is worse of than no CO2
at all. Run them on a timer to run at night to help with gas exchange. You can have high CO2
and high O2
in the tank at the same time.
is dropping the pH of the tank water a full 1.0 – 1.2. To do this, measure the pH of tank water with no CO2
dissolved in it, and then measure again 2-3 hours after CO2
has been running. Ensure the drop in pH is a full 1.0-1.2. If the drop is not there yet, slowly up CO2
over a few weeks until at least a 1.0 drop is achieved, and watch fish / livestock carefully. Adjust CO2
down if you notice fish gasping at the surface and consider running an airstone at night when pushing a 1.2 or greater drop. For example, a tank water pH of 7.5 with no CO2
dissolved in it, should reach a pH of 6.5 – 6.3 for CO2
to really shine, and for maximum plant health.
Consistency in CO2
levels is key to plant health. Keep CO2
levels as stable as possible once a desirable level has been reached.
On a 125... I would recommends buying a Dwyer RMA-150-SSV flow meter, this will allow you to track gas usage better than counting bubbles, I would think you need to be north of 10 bubbles per second to achieve a 1.0 drop in pH. Note that in any tank, a 1.0 drop would indicate roughly
30ppm of CO2
which is a good target to aim for. Run your filter outputs to create a small but noticeable ripple effect across the surface of the tank water to allow for good gas exchange, but not too much CO2
This would be ~25ppm - 40ppm actual, impossible for hobby grade equipment to tell, but note your drop in pH and keep it consistent. A $20 pH pen that can be calibrated off of Amazon is a great investment to a higher tech tank.