co2 chart

Discussion in 'Plant CO2' started by beginner, Dec 27, 2012.

  1. beginnerValued MemberMember

    anyone have the chart that shows the ph and kh and depending on those two levels gives you your dissolved co2 level?
  2. ryanrModeratorModerator Member

  3. Mer-maxWell Known MemberMember

    Google co2 ppm calculator and it does it for you
  4. chevyguy8893Well Known MemberMember

    A full 1.0 drop in pH=30 ppm of CO2, which is also the "ideal" level of CO2 in a high light tank. I found out that the CO2 chart, and the info I had posted in the other thread linked, was actually incorrect. The chart underestimates the CO2 ppm a pretty good amount. However, I don't have information on what the CO2 ppm is with the pH changes that are less than 1.0.
  5. AlyeskaGirlFishlore VIPMember

    Yeah, those charts aren't accurate.

    I go from pH 7.6 down to 6.3-6.4 and get good response from the plants; lots of pearling. Drop Checker reads yellow.
  6. catsma_97504Fishlore LegendMember

    The problem with those charts is that they fail to take all buffers into account. All it looks at is KH, but there are multiple other buffers. For example, phosphates. Don't use those charts or the quickie calculators. They will lead you down the path of too little CO2 and a very happy algae growth!
  7. Mer-maxWell Known MemberMember

    Does that go from 7.6 at night and 6.3 during the day ( co2 running time?)
  8. cichlidmacWell Known MemberMember

    Mine also drops almost 1 point Ph when running co2. Does this daily swing harm the fish? Since starting co2 a month ago I've lost 2 oto's.
  9. beginnerValued MemberMember

    my lights go out at 4 pm. last night at 9 when asked for the chart. ph was 8 and kh was 7. .just checked now( co2 has been off 45 minutes) ph is 7 and kh is 8. i'd say that seems right. one bubble a second in a 55 moderately stocked. guess I could shut the gas off a little earlier
  10. Mer-maxWell Known MemberMember

    I'm wondering the same thing. . .
  11. beginnerValued MemberMember

    bb use carbon to complete the nitrogen cycle, so over time with no water changes we see a steady decline in kh and ph. in this case you a dropping ph because you are losing you kh buffers. it the case with co2 you are forcing other compounds oh- or ho+..... something like that, to be created because you are dissolving the carbon into the water. I guess simply put and dnt quote me on this but tank water with a ph of 8 and kh 6 is the same as water of 7 ph with a kh of 8 with 30 ppm of co2 dissolved. sorry it is the fish that will you the carbon but its still part of the cycle
    Last edited: Dec 28, 2012
  12. jetajockeyFishlore VIPMember

    No. Swings in KH are the concern, people put way too much stock into pH readings.

    Just get a drop checker and make/buy some 4dkh water to make a reference solution, simple enough.
  13. AlyeskaGirlFishlore VIPMember

    This is with a pH Controller instead of a timer. Controller shuts off co2 at your desired lowest pH set point. PH will rise back up .02 difference and co2 will kick on again. Down side is co2 is being wasted at night. But pH is consistent.

    So, co2 is monitored by the Controller plugged into the solenoid 24/7.
    Last edited: Dec 28, 2012
  14. beginnerValued MemberMember

    I think when the lights go off the ph will then drop and turn off co2. it wont put out co2 at night
  15. catsma_97504Fishlore LegendMember

    There seems to be a bit of confusion; or at the very least maybe not communicating the intended message.

    There are several factors that fall under the water parameter umbrella. Within this umbrella are several subsystems. All in all, we are attempting to find that perfect balance to have a healthy, stable and thriving tank. Some of the commonly known subsystems include GH-KH-pH as well as Lighting-Fertilization-CO2 supplementation. We strive as good stewards to assimilate a closed ecosystem. Something goes out of balance, bad things happen.

    CO2 itself is a gas or a liquid (Excel) that is dosed in planted tanks for a carbon source. CO2 gas is held in suspension with the water column. It does not bind with anything. This is simply a property of water in that it is able to hold gaseous forms (saturation) due to the water tension at the surface. This is why a planted tank wants to minimize surface disturbance, to hold the CO2 within the tank and not allow it to escape. Dosing liquid carbon forms are different and do not follow these same rules.

    The same thing is true of the oxygen levels within the water column. O2 is held in suspension for the fish to utilize in their respiration. Deplete the water column of oxygen and the fish hang around the water surface, even gulping air trying to gain access to enough oxygen to simply breathe.

    Back to CO2 gas. When plants utilize carbon they break down the bond between carbon and O2. Plants consume carbon and the oxygen is used by the other inhabitants. It really is a very finely tuned ballet.

    CO2 gas acts as an acidic factor within the water column. While our test results pick up this difference, the actual pH of the water is unchanged. This is why we always ask members to test untreated tap water after it has been aerated for 24 hours. This aeration, creating surface disturbance, releases all trapped gases (CO2, O2, chlorine, etc). Then and only then can our non-scientific testing supplies provide a somewhat accurate pH level of the water itself.

    There have been many studies by others to test the affects of CO2 on the pH of the water. Those before us have determined that 30 PPM CO2 will supply enough of a carbon source to keep plants happy; and will not pollute the water column or deplete oxygen. Further, those who have completed the many studies have determined that CO2 has a logarithmic affect on pH, which is also logarithmic. While the results are mind boggling to me, the bottom line is that 30 PPM CO2 will in fact drop our pH results by 1 full degree so long as there is enough KH and GH to balance the subsystem.

    With at least 4 dKH and 4dGH the pH will drop one full degree when 30PPM CO2 is held in suspension. If the water's natural pH runs 7.2, then aim for 6.2.

    PH will fluctuate throughout the course of the day. This fluctuation is even greater in a planted tank. When we slowly increase the carbon levels fish adapt as as we would when being dropped off on the top of the Himalayas, for example. I believe this adaption is to the lowered oxygen levels, not to a change in pH. Anyway, a thriving planted tank will have a 0.4 degree change in pH, sometimes slightly higher, every day. The pH will be at its lowest about an hour before lights on and at its highest around lights off.

    I hope this makes sense. I have been interrupted several times; the last time was when my oven almost caught on fire. So, my head isn't exactly focused right now. If there are any I have not made clear, or caused confusion, please ask. The subject of carbon dosing is confusing enough!!
  16. cichlidmacWell Known MemberMember

    Well said professor :)
    I just want to add that a Ph of 6 is 10 times more acidic than Ph of 7 and a Ph of 5 is 100 times more acidic than Ph of 7.
  17. jetajockeyFishlore VIPMember

    I agree, although I understand it that o2 and Co2 don't displace one another. It's semantics, but the issue isn't a lower oxygen level but rather the creature having a harder time getting rid of the co2 in their systems in exchange for oxygen because of increased ambient levels. This is what I've gathered anyway from a few different plant specific forums.

    I have absolutely no background in biology though so I tend to defer to those who do, just thought I'd put that out there to toss around a little.
  18. catsma_97504Fishlore LegendMember

    That is a very good point jetta. One I haven't considered. I think of it as something along the lines of running an auto in a closed garage. CO2 does not necessarily displace O2. Instead, our lungs take in the CO2 much easier than O2. Maybe it is something like this for our fish?
  19. jetajockeyFishlore VIPMember

    Yes that's exactly what I was thinking. Like with a shuttle or some other sealed environment they have to use a method to remove the co2 from the system because everything would die no matter how much o2 they pump in.
  20. Mer-maxWell Known MemberMember

    Awesome. I'm glad I read this. But clearer now. Not so afraid of the ph shift anymore.