View Full Version : Controlling & measuring CO2 levels?
If I were to get a CO2 system to increase plant growth and health, how can I measure and control my CO2 levels so that I do not harm my fish?
Help appreciated!
Determining your C02 concentration is a snap if you already know your pH and KH levels. Once you've got your pH and KH test results, you can refer to a C02 chart like this one (http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html) to find your number. Controlling the C02 is achieved by adjusting the needle valve on the regulator. A bubble counter also comes in very handy in determining the rate of delivery.
:)
What if the KH of the water is too low to begin with (too soft < 4), and once CO2 is added it will drop even more. How can I increase the KH if needed? I am asking this because the pH in my aquarium is already 6.8, and if I add CO2, it will drop the pH to dangerous levels for the fish.
OrionGirl
09-02-2003, 12:54 PM
http://www.skepticalaquarist.com/ Should be of some assistance in altering your KH.
Are you certain that your plant growth is currently limited by low CO2? If not, supplementing it may not result in the growth you're looking for, and cause additional headaches.
Pink Pat
09-02-2003, 7:13 PM
Dado,
With a KH of <4 and a pH of 6.8 you already have approximately 15-20 ppm of dissolved C02. Not a bad range. If your plant growth is slow, it could well be something (read lighting) else.
HTH
PP
NJ Devils Fan
09-04-2003, 3:57 PM
This is my favorite CO2 Chart (http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm). I even printed it out and laminated it because I use it a lot.(even though there really is no need to have done that, I felt i should anyway.;) )
Pink Pat
09-04-2003, 7:11 PM
NJDF,
That is indeed a great chart and the explanation of the pH/KH/C02 relationship is even better. It dispels a lot of misconceptions. Thank you for posting the link.
PP
NJ Devils Fan
09-04-2003, 10:33 PM
No problem, print it out an laminate it like I did.;)
carpguy
09-04-2003, 11:12 PM
Originally posted by Pink Pat
With a KH of <4 and a pH of 6.8 you already have approximately 15-20 ppm of dissolved C02. Not a bad range.
But its not an ambient range.
It might be the readings straight from the tap or it might be inaccurate readings or it might be inaccurate tests, but you won't have 15-20 ppm in a tank without supplemental CO2.
If you're concerned about overly low KH, some crushed coral in the filter will do the trick. I have minimal (<1 d) KH in my tap and I'm very happy with my CO2 tank. I have a little mesh bag of crushed coral sitting in my filter. Its very workable without a lot of fuss. The Skeptical One (http://www.skepticalaquarist.com), as ever, has the details.