good question

[sergo]

i was looking at the co2 saturation chart and said to myself, "self, if your ph is 7.2 and your kh is 8 would you really have a co2 concentration of 15ppm and is it really necessary to do co2 injection?"
anyone??????
my water is at that right btw.

[Drumachine09]

i was looking at the co2 saturation chart and said to myself, "self, if your ph is 7.2 and your kh is 8 would you really have a co2 concentration of 15ppm and is it really necessary to do co2 injection?"
anyone??????
my water is at that right btw.

Cueing Chrona in 3...2...1... Now!


lol.

[sergo]

:ezpi_wink1:
Cueing Chrona in 3...2...1... Now!


lol.
right!

[cocoa_pleco]

call 1800-help-me-chrona:hmm3grin2orange:

[Chrona]

Here's how to interpret the chart. First off, you don't have more than 3-4 ppm CO2 if you don't inject it, period (Less if you have lots of surface agitation). The idea behind the chart:

kH raises pH by a certain amount. For instance, 4 dH of kH would mean a normal pH of 7.6 or so. This is assuming you have no pH affecting chemicals/material in your tank. CO2 drops pH by a set amount, dependent on the concentration. 30 ppm of CO2 drops pH by exactly 1.0. Thus, looking at the chart, if you have a kH of 4, you normally have a pH of 7.6. If you are injecting CO2 and your pH is now 6.6, that's a drop of 1.0, which the chart shows as 30ppm of CO2. So for a known kH and a pH, you can figure out the CO2 concentration (only if you are injecting it. Nothing's free :P)

[Chrona]

As a side note, the chart isn't entirely accurate, since pH and kH measurements are pretty bad going off the chart usually, which is why most people use a drop checker to test CO2 levels. Basically it's a small container that holds a small volume of very precise 4.0 dH kH, along with a few drops of pH solution. The solution is kept seperate of the tank water, but the CO2 in the water diffuses into the air in a small space above the solution and eventually into it. The color of the drop checker solution then, tells you the CO2 levels at a glance. Green = good, blue = low, yellow = high. The solution lasts for like 3-4 months. Just got one myself, handmade by someone on another forum for 7 bucks shipped. It's pretty cool imo. If you look at my tank journal, it's the thing in the upper left hand corner of the tank.

[sergo]

that's kind of what i thought, damn.
so basically you have to judge the amount of ph drop by the kh to figure concentration co2.
i got it.

[sergo]

As a side note, the chart isn't entirely accurate, since pH and kH measurements are pretty bad going off the chart usually, which is why most people use a drop checker to test CO2 levels. Basically it's a small container that holds a small volume of very precise 4.0 dH kH, along with a few drops of pH solution. The solution is kept seperate of the tank water, but the CO2 in the water diffuses into the air in a small space above the solution and eventually into it. The color of the drop checker solution then, tells you the CO2 levels at a glance. Green = good, blue = low, yellow = high. The solution lasts for like 3-4 months. Just got one myself, handmade by someone on another forum for 7 bucks shipped. It's pretty cool imo. If you look at my tank journal, it's the thing in the upper left hand corner of the tank.that's just too much now. i want nice plants but i'm not gonna spend every spare moment on them. i'll stick slow but sure growth (with a side of diy co2 :)-)
thanks for the info though.

[Chrona]

that's kind of what i thought, damn.
so basically you have to judge the amount of ph drop by the kh to figure concentration co2.
i got it.

The pH drops by 1.0 with 30ppm of CO2 regardless of kH. The only time this breaks down is if you have less than 1.0 kH, where you may get pH swings because your buffering ability is so low. This is the premise behind the degassing method, where you measure tank pH, leave a cup of water sitting for 24 hours, and measure pH again when the CO2 level has dropped to 3-4 ppm again. 0.5 pH rise = 15 ppm CO2, 1.0pH rise = 30 ppm.

[Chrona]

that's just too much now. i want nice plants but i'm not gonna spend every spare moment on them. i'll stick slow but sure growth (with a side of diy co2 :)-)
thanks for the info though.

Right, but the drop checker means all you need to do to check CO2 is to glance at the thing :)

[sergo]

i may just try that and see where i am.