Thanks for the link. I'm not sure I'll ever find one that costs less than £20
It seems my package is not moving at all, I decided to buy a new digital ph device to get some measurements. Calibrated it and started testing a few hours ago:
Before CO2 = 7.22 Ph
1 hr = 6.77
2 hr = 6.58 (lights on).
With a KH of 4 this puts me at 31 ppm CO2 after 2 hours (and 7 ppm to start with). Since my KH is dropping fast in the new setup, I need further testing / tweaking CO2 the next couple of weeks / months.
Will keep testing the rest of the day, and crank it up a bit tomorrow
Hi @kilnakorr
Thanks for the update.
Some people have paid less than £20 from eBay. But then run into inaccuracies, etc. I'd be interested in knowing which manufacturer and model number you chose. But, obviously, if you'd rather not say, then no problem.
So, you now have some measurements. I would suggest that 31 ppm CO2 after 2 hours is pretty good. You'll no doubt be aware that the well-known KH/pH/CO2 table is not 100% accurate. That's because other ions and compounds affect the water chemistry. I'll be interested to know at what level the CO2 stabilized with lights on.
Having new soil in tank so kh/ph is not an option as this would read 200-300ppm co2.
What happened about the CO2 from the soil substrate? How did you derive the figure of 200-300ppm CO2?
Is your water KH reasonably stable now and what figure(s) are you seeing?
JPC