Injected co2 question

Discussion in 'Plant CO2' started by Mer-max, Dec 27, 2012.

  1. Mer-maxWell Known MemberMember

    Do you turn your regulator off at night? I'm wondering if I want a regulator with a solenoid or if I want one ( free ) from a cutting torch o2 bottle. Would the freebie work? Also - I'm wondering about the cutting off at night b/c wouldn't that make your ph drift a lot ( cutting it on and off?)

    Wouldn't I just want to run the co2 ALL the time and just break out the air stone at night?

    Clarification would be awesome, thanks!
  2. ryanrModeratorModerator Member

    :;du Thread moved to Plant CO2 forum

    I'm not sure how it works with pressurised CO2, but with my DIY, I just ran the air at night.

    I believe many pressurised users turn the CO2 off at night (lights out) due to plants producing CO2 at night. Coupled with CO2 injection, I believe you run the risk of adding too much CO2 over night.

    Let's wait for pressurised users to chime in.
  3. Mer-maxWell Known MemberMember

    That's what I was thinking - to cut it off about an hour before lights out but was afraid the ph would jump back up - my water is normally 8.3-8.4
  4. chevyguy8893Well Known MemberMember

    Do not use a regulator meant for industrial use, they don't maintain a steady rate of CO2 flow (since they don't need to) and could quickly kill everything in the tank.

    I have a solenoid on mine, plugged into a timer, that turns on 1 hour before the lights, and shuts off an hour before the lights go off. To me it is just a waste to run the CO2 all night since it isn't used by the plants. I also don't use an airstone at night, but that is not something that works for everyone. The CO2 pH change doesn't cause problems with the fish since it is only a change in the pH, and it doesn't change any of the other parameters.
  5. Mer-maxWell Known MemberMember

    I thought ph was supposed to be really steady? With DIY co2 at night my knife fish started acting wierd half laying under a log and drifting sideways almost as if to lay on his side so I stopped running it. You can control the flow on an acetylene regulator - why wouldn't it be consistent?

    All my other levels stay pretty good. I actually have trouble keeping nitrate up for the plants. I can dose flourish nitrogen in the morning and come home to less than 5 ppm
    Last edited by a moderator: Dec 27, 2012
  6. chevyguy8893Well Known MemberMember

    Yes, pH should be steady under normal conditions, but when pH swings, without CO2, it also has changes in the KH which causes problems with the fish. Even under normal conditions there is some change in pH at night because of live plants releasing CO2 along with the fish waste. This is all how I understand it, but the explanation could be wrong. I have GBR's, which are notorious for needing stable and pristine water, in the tank with pressurized CO2 and they don't have a single problem with the pH change from the CO2.

    I have heard that some fish are sensitive to CO2 in the water if the oxygen levels are not high enough, but I cannot say for sure what is going on there.

    From what my welding store has told me, the welding regulators do not need to maintain a very steady flow since they are generally opened up all the way. I don't know how true that is, but one person around here did try it and had everything set up at a low level (apparently 1 bubble per second), and a couple hours later the rate had gone way up and all the fish were dead. Similar things have happened with people using paintball CO2 tanks with a needle valve to control the flow. You may be able to look into the regulator type (flow or pressure regulator) to see if it can be converted to be safe, but I don't know the details of doing so.

    How often do you dose the flourish nitrogen and what ppm does it go to? I keep mine pretty low for my GBR's with KNO3 dosed every other day. At most I am between 5-10 ppm after dosing, and by the next dose it is almost 0 ppm. There haven't been any deficiencies show up because of it.
  7. catsma_97504Fishlore LegendMember

    The above information is quite accurate. Welding gases simply are off or on. The fine control required to use CO2 in an aquarium demands finite control to avoid killing the inhabitants.

    A DIY system requires the use of an O2 line during the lights out period since you cannot turn off the gas being produced without risking a buildup of CO2 around the tank or leading to an explosion from gas building up within the generator bottle.

    With an injected system, it pushes so much CO2 into the tank that the fish would perish overnight if not turned off. This, of course, assumes you are dosing 30PPM during the daytime. This coupled with plant respiration would push the level high enough that there would be almost oxygen left in the tank.

    If you are going to use an injected system, there are no cheap shortcuts that do not risk the lives of those under your care. Purchase a regulator with fine needle control and with a solenoid. And plug the solenoid into a timer or use a pH controller.

    As for pH fluctuations, that is the expected norm in a planted tank. Something that can be difficult to comprehend is that while the CO2 reduces pH on our test kits, the fact remains that the actual pH of the water remains unchanged. You should expect the pH to fluctuate by 0.4 degrees during the course of a day. No, this does not cause a negative impact to the inhabitants as they can adapt to the small pH changes. It is the larger swings that we must be cautious of.
  8. jetajockeyFishlore VIPMember

    The way I understand it is Co2 is acidic and will lower pH while O2 will raise it. Both are irrelevant though with regards to stock (regarding swings) as long as one has a stable KH. The hardness swings are where people run into problems.

    I have a solenoid on my co2 regulator that shuts off when the lights go off every day.
  9. Mer-maxWell Known MemberMember

    So the kh won't move around? It took like 38 drops to get the solution to turn yellow
  10. beginnerValued MemberMember

    whats your ph? I just saw that is 8.3. well its off the chart that I have but it could be close to what you want. I have a 55 and I just run 1 bubble a second. and that just bc its 35 bucks to fill a 10 pound bottle. i'm sure I could run more
    Last edited: Dec 28, 2012
  11. Mer-maxWell Known MemberMember

    Also - if I run the DIY co2 until I can get a regulator will the ph/kh calculator show my true co2? I had like 4 ppm or so last night
  12. beginnerValued MemberMember

    for your true co2 you'll need a drop checker, maybe someone can explain that to us
  13. Mer-maxWell Known MemberMember

    I don't really Care what the ph is - as long as its stable.

    How long does the bubble a second take to deplete your tank? And what ppm does it make your co2?
  14. AlyeskaGirlFishlore VIPMember

    Drop Checkers are slow at changes and should not be relied on for that reason. Though they still are nice to have. Fish behavior and plant response are what you need to go by when injecting co2.

  15. Mer-maxWell Known MemberMember

    I guess tomorrow morning I will try the DIY again. See how my knife fish is doing at the end of the day, I guess I could always pull the end of the line up out of the water at night
  16. beginnerValued MemberMember

    a 10# bottle doesn't quite last a year. well if I had a drop checker I could tell you the day time ppm I've had for the last 2 years. otherwise its just one bubble.

    welding reulators maintain a very accurate flow of gas, but they have a minimum regulated flow rate. oxygen gets regulated a 40 psi acetylene at 8. personally I have a hydroponics regulator with a needle valve and soleinoid. pricey but top quality.
    Last edited by a moderator: Dec 28, 2012
  17. Mer-maxWell Known MemberMember

    What do you think of this regulator?
  18. beginnerValued MemberMember

    not bad. wish mine had a bubble counter on it.
  19. Mer-maxWell Known MemberMember

    Also - trying to clarify - its ok to run the co2 during the day and just pull the diffuser out at night, correct?
  20. beginnerValued MemberMember

    are you talkin diy or are you talkin injected?