This site is supported by the advertisements on it, please disable your AdBlocker so we can continue to provide you with the quality content you expect.
  1. Support us by upgrading to the lifetime advertisement free version.

    Click here for more information.
    Dismiss Notice
  2. We are after as many aquarium plant images that we can get, doing so will assist us in completing the aquarium plant database.

    https://barrreport.com/threads/aquatic-plant-images-wanted.14374/
    Dismiss Notice

Having trouble keeping my co2 levels up

Discussion in 'CO2 Enrichment' started by Gwendelion, Mar 14, 2017.

  1. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I have a 120 gallon tank, my tap water pH is 7.8 and KH 5 so I'm going for an end of day pH of 6.7. For the last two weeks though it's been dropping less and less throughout the day until it stopped dropping at all, so I left the co2 on overnight for a few nights. The morning after the first night the pH was 6.7, exactly where I want it, and by 3 pm it was 7.6+ (I didn't bother figuring out what exactly it was, that was too high). I left it on overnight again and the next morning the pH was still 7.6+. I bumped up the bubble rate to a stream but the pH stayed there through the day and is the same this morning.


    Three or four weeks ago I put a Rex Grigg style reactor on, replacing a leaky MaxMix reactor. I don't know if it's related - seems like it should be working better now, not worse - but it's worth mentioning. I also put a surface skimmer on the tank several days before this started, and I suppose that could contribute to the problem, so I turned it off this morning to see what happens.


    Any ideas what the problem is or how to fix it? It seems very odd that the pH is going up through the day, when the co2 is on. And it's giving me algae.
     
    #1 Gwendelion, Mar 14, 2017
    Last edited by a moderator: Mar 14, 2017
  2. Pikez

    Pikez Rotala Killer!
    Staff Member Moderator

    Joined:
    May 12, 2013
    Messages:
    1,962
    Likes Received:
    1,473
    Local Time:
    12:02 PM
    Use process of elimination to get to the root cause.


    It's not the skimmer. Skimmers can't cause that much of a issue.


    On a big picture level, you're either working with a faulty probe or not not dissolving the CO2 into the water.


    Probe is easy to check. Buy 7.0 buffer and calibrate once a month or every other month. Once you do that, you can eliminate that as a source of the problem.


    You're left with the reactor. That's my suspect. You may have a leak somewhere. Check all connections with soapy water - see if you are getting bubbles and foam at any of the connections. Check for blocks.
     
  3. tinkerman

    tinkerman Subscriber

    Joined:
    Dec 8, 2007
    Messages:
    126
    Likes Received:
    2
    Local Time:
    12:02 PM
    How it the reactor plumbed? How much circulation is in the tank?


    I have a 120 and have noticed PH doesn't drop as much when canister is getting dirty, surface ripple decreases. Need a little more info on your tank. I have a fuval fx5 and 2 tunze 6105 cranked.
     
  4. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I'm checking pH with an API test kit and using a drop checker to keep an eye on it as well.


    I checked the reactor for leaks yesterday, and just checked again to be sure, but I didn't find any. The co2 line connector to the reactor body is a slightly translucent white and I can see a little water backed up into it and co2 bubbling through that into the reactor. Which would make me think it's just not enough co2, except that it has been in the past...
     
  5. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    The reactor is plumbed inline with a Fluval 406 after the filter, then to in inline heater. I can take pics.


    I cleaned the filters on sunday, they seem to be putting out good flow but I have no way to objectively measure that. I also have a Fluval 306 on the opposite end of the tank, which is where the surface skimmer is.
     
  6. rajkm

    rajkm Article Editor
    Staff Member Lifetime Member Article Editor

    Joined:
    Sep 16, 2015
    Messages:
    677
    Likes Received:
    218
    Local Time:
    12:02 PM
    Check your KH. Do you have any rocks that would alter water parameters. Does the PH go back down after water changes?


    With Rex Griggs, you need to make sure that there is not too much pocket of gas/air on top. else it becomes less effective. You can counter that by drilling a hole on top, add a airline tube attached with a valve which when you turn will bleed the air/gas from the top.


    Reduce bends in pipe too, so the flow should not be reduced. You could be adding too much gas compared to the flow, which could also lead to build up of gas.
     
  7. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I do have seiryu stone, and aquasoil. I just tested the KH, it's 5, which is the same as my tap water which I also just tested, so I don't think they're affecting the KH. The GH in the tank is higher than my tap, 4 in tank and 0ish from the tap. Which is confusing because I do have a KCL water softener, but the salt hasn't been filled for a while and the tap GH was 8 when I've tested it over the last three weeks or so. Connection?


    The pH does not usually go down more after a water change.


    Interesting that I could have had the opposite effect by adding more co2 because of buildup in the reactor. That could be my problem.


    In the photos you can see the reactor has a valve on it, which I think is to increase flow if you have a filter with really high gph. I've had it partway open before and I could hear water trickling inside so I figured my flow was too low to need it. I wonder if I can work some air out by opening and closing it though.
     
  8. puopg

    puopg Guru Class Expert

    Joined:
    Nov 19, 2012
    Messages:
    214
    Likes Received:
    0
    Local Time:
    12:02 PM
    To me, sounds like you have a leak somewhere. I find it hard to believe that you can't even drop the pH at all when CO2 is on. I only reccommend looking for a leak somewhere since I just found a leak in my system yesterday. I was wondering why I couldn't drop the pH even though I bumped the dial up a lot. Turns out when I was spraying different joints with soapy water, I accidentally touched my check valve and heard a hiss. Turns out the tubing that was connected to my check valve was not tight enough. Might want to just check different joints, you may find something.
     
  9. tinkerman

    tinkerman Subscriber

    Joined:
    Dec 8, 2007
    Messages:
    126
    Likes Received:
    2
    Local Time:
    12:02 PM
    You will loose flow through your reactor as your canister gets dirty, so your co2 will decrease as the flow slows. Does the drop checker say you have good co2? I would go by the drop checker over a API PH test. If you had a co2 leak I would guess it would be from the plastic check valve but wouldn't hurt to check everything from the bottle down the line. I have used the plastic check valves in the past and they leak or fail in a short time frame. Never had any luck with reactors, I use diffusers under a power head and blow the mist around the tank. There are a 1,000 ways to skin a cat, what one might do to their tank may not work for you. What is the black box just below the power strip? If possible I would put the heater before the filter as it will decrease head pressure on the filter. You have a lot of right angles in the plumbing, adds to head pressure and reduces flow.
     
  10. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,695
    Likes Received:
    736
    Local Time:
    12:02 PM
    KH of 5, you should be in the pH 6.5 ranges. Good flow is key to stable CO2 for reactors, which is why canisters that clog, are not good to use for in line CO2 systems.
     
  11. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    This morning the drop checker was green and the pH tested at around 6.7 after leaving the co2 on all night again. I submerged my bubble counter and check valve, and am sure neither leak. It now seems most likely to me that air is building up in the reactor and causing it to be less effective.

    The drop checker has been staying blue-green. It was green this morning though. The pH test kit has always agreed with the drop checker also.


    I do need to get another check valve, I thought I had a better one but couldn't find it, so this "temporary" one has been on it for too long.


    The black box below the power strip is the control box for my Current USA light.


    The heater needs to be vertical and I don't have space for that before the filter, the tubing would have to make a sharp turn back upward to the filter. The head pressure could be part of my reactor problem.


    I've heard putting the heater before the filter is bad for the motor also, because of the added heat?

    Do you prefer sumps then, or just particular canister filters?


    I don't think I have ever gotten my pH to 6.5 0_o
     
  12. rajkm

    rajkm Article Editor
    Staff Member Lifetime Member Article Editor

    Joined:
    Sep 16, 2015
    Messages:
    677
    Likes Received:
    218
    Local Time:
    12:02 PM
    I don't know how good those Rex Griggs with bypass are. There are design flaws with it because rexgriggs works on CO2 dwell time. The bypass model people have created has CO2 injecting at the shortest section. If you close the bypass the CO2 will build up after the bypass valve in the lower section. You need the valve at least partially open to let the gas go back up towards the top so water can push the gas back down to dissolve. If you open the valve too much the flow in the CO2 injection area is reduced because water will take the less obstructed path, so you will need even higher flow.


    Just few of the things to think about.
     
  13. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    Hmm maybe if I just crack the valve it will help...


    I'm a little annoyed with the company I bought the reactor from, because I had asked them what size would be appropriate for my tank and filter before I bought it, and this was their recommendation. But I really think you would need something like an fx5 with this one.
     
  14. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I left the valve open a little, the pH went up overnight again with the co2 on. So that didn't help...
     
  15. rajkm

    rajkm Article Editor
    Staff Member Lifetime Member Article Editor

    Joined:
    Sep 16, 2015
    Messages:
    677
    Likes Received:
    218
    Local Time:
    12:02 PM
    Hmm... more likely or not it's flow problems, but before we get down that path, do you have any other diffuser?


    we need to take other problems out of the equation before tackling the reactor now.


    if you have a ceramic diffuser or a power head where you can connect the CO2 to the intake then we should try that and see. If that works then the reactor is the issue. If not then we can assume something is going on in the tank.


    Also stop the skimmer until you figure it out. I recently got a skimmer and found it can increase my PH by 0.2 in little over 1 hour. I didn't keep it on longer to see how far it can increase. It will stabilize the flux eventually but let's take that out of the equation too.
     
  16. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I don't have another diffuser. I could get a powerhead, I've just never found that to be very effective with the one I have, even in smaller tanks. Maybe I could figure out a better setup for it that what I had done before.
     
  17. tinkerman

    tinkerman Subscriber

    Joined:
    Dec 8, 2007
    Messages:
    126
    Likes Received:
    2
    Local Time:
    12:02 PM
    What model power head and how did you have it set up before?
     
  18. Dennis Singh

    Dennis Singh SynKing!

    Joined:
    May 5, 2013
    Messages:
    2,417
    Likes Received:
    639
    Local Time:
    4:02 AM
    You got any rocks buffering your ph up?
     
  19. Gwendelion

    Gwendelion Subscriber

    Joined:
    Sep 26, 2016
    Messages:
    15
    Likes Received:
    0
    Local Time:
    12:02 PM
    I do have seiryu stone, but the pH seems to stay pretty stable, it doesn't go up over what my tap water tests at.


    I've decided to try to just start over. I purged as much air as I could out of the reactor by turning off the co2, opening the valve all the way and unplugging the filter then plugging it back in until it pushed all the air out and I no longer hear any trickling inside it. Then I started the co2 back up at 1bps and am bumping it up by about 1 bps per day until I either get the desired pH change or get a buildup of air, whichever happens first. If it seems like I can't get the reactor to work correctly I guess I'll get a diffuser.
     
  20. Dennis Singh

    Dennis Singh SynKing!

    Joined:
    May 5, 2013
    Messages:
    2,417
    Likes Received:
    639
    Local Time:
    4:02 AM
    You'll never get the right readings with kh/gh constantly changing through your rocks, so your readings will be off.


    Are you able to gas fish?


    get back the surface skimmer. Good for the fish


    If its not the rock, then the issue is tank size, you will have / need better diffusion methods


    like 2 reactors


    I have no doubt your reactor is working, they're not efficient as cerges, but good enough, you may need another, a diffuser will go absolutely nowhere in 120 unless your doing low tech.
     
    #20 Dennis Singh, Mar 23, 2017
    Last edited by a moderator: Mar 23, 2017
Loading...

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice