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. 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

Decreasing c02 - observations

Discussion in 'CO2 Enrichment' started by Gerryd, Dec 9, 2013.

  1. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    Hey all,

    The following is not scientific at all but simply observations over 2-3 months.

    A big assumption here is that I think I was injecting WAY TOO MUCH C02 into all 3 of my tanks, and have been overdosing c02 for years now.

    So, I had many issues with my 2 smaller tanks. Poor growth, explosive and constant BGA, and some BBA as well. The poor growth was what really concerned me. I kept up my maintenance, large weekly water changes, dosed EI, did some 2 day black outs, etc. Nothing really worked.

    I decided to simply step back with c02 and start over. I simply turned the needle valve back until I could easily count the bubbles. Then gave it a few more notches on the vernier, and went from there.

    Visually, using the displacement method, and by tank fill duration, this was a HUGE REDUCTION in c02 rate. I did NO OTHER CHANGES that I can think of.

    Within a week both tanks had the BGA gone and I could see some new growth. Within 2-3 weeks the growth on the 57 was explosive in terms of the rotala green Tom sent over. Even downoi has grown, as well as other plants Tom sent over.

    The same for the 75 but the growth was not as explosive, as I have ferns mostly. But, the bolbitus got huge again (was stagnating for weeks) and the java is regenerating nicely.

    I left lights, ferts, surface ripple, filtration, dosing, etc the same as far as I can tell.

    I cannot explain it other than to think I was injecting so much c02 that it either forced out too much 02, or something else.

    I am NOT stating direct cause and effect here. Just observing that a large reduction in c02 rate was positive for 2 tanks.

    This has been steady now for 3 weeks and growth continues to improve in both tanks.

    ******

    I have also been reducing c02 in my 220, but that is simply trying to adjust downward. I get good growth now but I feel again I am overinjecting. So, small changes every 8 days for 5-6 adjustments so far, has not had any adverse impact. Growth is strong, no algae, all good.

    I will continue to SLOWLY adjust over time unless/until I see growth degradation or algae or some kind.

    The grass is very well established and RARELY uprooted except for edging. Even that is very limited in area each time and is only every 4-6 weeks.

    I will continue to monitor but things seem on a positive path.

    Hope to post some media soon of all 3 tanks. Most likely with be photobucket links as pics attached cause the web display to go very wrong for me.

    Thanks for listening and take care!
     
  2. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Maybe it was just the tanks finally rooted and are doing well and the CO2 was overdone during that time and backing off, using less species, having less competition between plants for light/CO2 made a lot of differences?

    I can tell you, under no way can this occur in any of my tanks at home. I see it right away. 1-2 days, algae, smaller growth etc.
    There's no reason much like ferts and adding more than you need, that backing off and slowly observing things is not a bad method.
    We did this with a client in LA for his discus.
    Roughly 40 ppm was the target that worked.

    I've seen plenty of folks do this in the past, and I've also seen plenty that went too far and once you get those algae, well........
    It's not as simplistic. The observations and common sense clearly suggest that it's not simplistic.
    You CANNOT force out O2 using CO2. They are independent.

    Some plants may melt, some may get BBA, some might have smaller tip growth, those are the issues to look for. As biomass increases, the demand for O2 goes up at night.
    But more O2 during the day and more CO2 demand.

    Just keep that in mind.
     
  3. Matt F.

    Matt F. Lifetime Charter Member
    Lifetime Member

    Joined:
    May 30, 2009
    Messages:
    2,319
    Likes Received:
    4
    Local Time:
    11:38 PM
    This is totally weird that we posted basically about the same observation. Your experience mirrors mine.

     
    #3 Matt F., Dec 10, 2013
    Last edited by a moderator: Dec 10, 2013
  4. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Don't you both have established Belem hair grass mostly?
    Once my belem grew in the 70 Gallon, I had few issues after.
    Ferts or CO2.
     
  5. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Don't you both have established Belem hair grass mostly?
    Once my belem grew in the 70 Gallon, I had few issues after.
    Ferts or CO2.
     
  6. Matt F.

    Matt F. Lifetime Charter Member
    Lifetime Member

    Joined:
    May 30, 2009
    Messages:
    2,319
    Likes Received:
    4
    Local Time:
    11:38 PM
    Yes, we both have E. Belem.

     
  7. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    Tom,

    Yes I have belem, but I am referring to the OTHER 2 tanks I have. The 220 has been good from day 1 of the new scape. I am simply adjusting the 220 co2 rate is all.

    The 2 smaller tanks did not do well at all really. I had a bubble rate of >150 ml per minute. I simply lowered it to a few bps and the turnaround has been dramatic on 2 tanks. Nothing else really changed that I can see. They had been languishing for weeks before this.

    - - - Updated - - -

    Tom,

    Yes I have belem, but I am referring to the OTHER 2 tanks I have. The 220 has been good from day 1 of the new scape. I am simply adjusting the 220 co2 rate is all.

    The 2 smaller tanks did not do well at all really. I had a bubble rate of >150 ml per minute. I simply lowered it to a few bps and the turnaround has been dramatic on 2 tanks. Nothing else really changed that I can see. They had been languishing for weeks before this.
     
  8. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    That was a very excessive rate for such smaller tanks.
    Something else was up.

    A 75 like yours, maybe 4 bubbles a second might seen pretty high.
    The 57, maybe 3. As the tank sizes go up, the degassing rates go up.
     
  9. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    That was a very excessive rate for such smaller tanks.
    Something else was up.

    A 75 like yours, maybe 4 bubbles a second might seen pretty high.
    The 57, maybe 3. As the tank sizes go up, the degassing rates go up.
     
  10. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    Hi Tom,

    I completely agree. I am NOT arguing for MOST folks to decrease c02.

    That said, I waited another 12 days before responding to guage the growth and such. Both tanks continue to do very well and may NOW have a rate closer to what you suggest above. However, I have NOT decreased further the rates in either small tank. they remain as set a few weeks back.

    I will do the displacement method for all 3 tanks over the next few days and publish.

    I am doing my best to NOT think direct cause and effect, but I think that FLOODING the tank with VAST amounts of c02, causes issues somehow, that is apparent.

    I am NOT going to revert back to the previous rates just to see :) I don't want to revert back to the poor plant health either.

    A. reneicki that had curling new leaves are now long and well formed. Java ferns are now fuller ever other day. I even have DOWNOI growing in BOTH tanks, and so far after 2-3 weeks already have BETTER growth than the many times I tried in the 220 lol

    Not huge by any means, but good new growth, branching, and such. Only a matter of time now I think.

    I trimmed the 57 yesterday as the growth had taken over..

    It will be interesting to see the displacement for each tank.

    Oh, I also lowered the 220 rate again today for like the 7th consecutive week with no ill effects so far. Again, this rate is way out of proportion to what I think it needs. Plant growth continues to be fine and algae has not grown any more than before.

    I simply think over time I went crazy with rates, which explains why I always had a rapid rating of 5 for surface agitation :)

    I am open to more ideas for root cause other than simply overdosing, but both tanks went from crap to great by a huge decrease in bubble rate. The sequence of 220 rate decreasing also leads me to suspect I am way overdosing.

    I swapped to a new 20lb on the 220 yesterday, so will see how long it lasts..

    Thanks and take care.
     
  11. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Remember as you hit that point where degassing rates really increase as you push the ppm's, since concentration is the only change to Fick's 1st law.
    So it's mostly change in concentration = rate of degassing.
    You have a sump, surface skimming, so the surface is not much of an issue.

    That's pretty stable.

    So say you want 60 ppm/relative pH of 5.8 for your tank and you have to add say 5000mls/hr to get that ppm or a relative pH.
    Then you add only 3000 mls/hour to get a CO2 ppm of say 45 ppm or a relative pH of 6.0.
    You use much less gas, but the tanks still do pretty good.

    You drop the CO2 ppm/pH but roughly 33%, but you add 40% less CO2 gas by volume.
    I do recall the LED lights are not that powerful, that was a fairly weak spread and in the 40 umol range. I forget the 57, but......if you ran at say 90+ umols, well.......

    Much like EI, you can start high with CO2, then slowly taper and then bounce back up to the last highest ppm/ relative pH.
    But stunted plants, algae etc are more often the signs you need more CO2, which is not as easy to adjust as ferts which are much more forgiving.
     
  12. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Remember as you hit that point where degassing rates really increase as you push the ppm's, since concentration is the only change to Fick's 1st law.
    So it's mostly change in concentration = rate of degassing.
    You have a sump, surface skimming, so the surface is not much of an issue.

    That's pretty stable.

    So say you want 60 ppm/relative pH of 5.8 for your tank and you have to add say 5000mls/hr to get that ppm or a relative pH.
    Then you add only 3000 mls/hour to get a CO2 ppm of say 45 ppm or a relative pH of 6.0.
    You use much less gas, but the tanks still do pretty good.

    You drop the CO2 ppm/pH but roughly 33%, but you add 40% less CO2 gas by volume.
    I do recall the LED lights are not that powerful, that was a fairly weak spread and in the 40 umol range. I forget the 57, but......if you ran at say 90+ umols, well.......

    Much like EI, you can start high with CO2, then slowly taper and then bounce back up to the last highest ppm/ relative pH.
    But stunted plants, algae etc are more often the signs you need more CO2, which is not as easy to adjust as ferts which are much more forgiving.
     
  13. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    EDIT: I made a mistake in the two tanks that I reduced. It was the 57 and the 220 where I reduced the PSI and NOT the 75.

    That said, I see no issues over 11-12 days in the 220. The belem seems fine as do the other plants I have. No algae growth either.

    I apologize for that.

    I really think that over the years I have been overdosing on c02 into the tanks. I have made enormous reductions in c02 gas provided to all 3 tanks over the last 3 months, and so far no issues. The two smaller tanks have done BETTER since the reductions, while the 220 seems the same plant growth wise.

    The fish all do seem more active during the c02 period which would also make sense. I see a tiny bit more pearling in the 22o hair grass.

    Sorry and thanks.


    Hey all,

    Happy New Year to all!

    I wanted to provide a quick update or two..

    1. Approx 11-12 days ago now, I decided to further reduce the c02 gas rate into both the 75 and th 57 gal.

    2. I did this by reducing the PRESSURE on the regulator instead of using the needle valve (NV).

    3. Both regs read approx. 18 psi or so. I dropped both to 13 psi and left it alone after that.

    4. I monitored to ensure the new psi remained as set and watched the tanks.

    So far all seems well.

    1. I see NO increase of algae of any kind.

    2. Plant growth continues to be pretty good, I have DOWNOI growing in BOTH tanks, and while they are not huge crowns (yet) they are healthy and growing/spreading. Both get 50 PAR tops for about 6-7 hours.

    3. I had culled the green rotala in the 57 and new tops developed AFTER this reduction and it is doing well. The macrandra and other plants are doing well in this tank.

    4. The ludwigia perunesis in the 75 is doing well and leaves continue to grown in size and with better color as they mature and get closer to the light.

    5. The ferns all continue to do well.

    So, I am going to leave as-is for awhile and see what develops. I have not yet done the displacement measurement as I had company and the holidays and all that kept me occupied.

    I am happy that good growth continues and for sure I am using less co2, just by visual bubble rate and the mist going into either cerges.

    Tom always says it is plant growth to monitor and the plants are doing well. I see no new algae nor growth of existing. No real reduction in the bits of BBA but there was not much to begin with. No hair or bga or anything other than gda.

    So, at least I can conclude that I was using way too much c02. Certainly a lower pressure and bubble rate is being used.

    I will test and publish the displacement values soon I hope.

    I next need to get some more fish. Both laetacara pairs are with fry and this seems regular now.

    Thanks for listening and hope all is well.
     
    #13 Gerryd, Jan 1, 2014
    Last edited by a moderator: Jan 1, 2014
  14. Matt F.

    Matt F. Lifetime Charter Member
    Lifetime Member

    Joined:
    May 30, 2009
    Messages:
    2,319
    Likes Received:
    4
    Local Time:
    11:38 PM
    I've reduced the amount of gas into my tank, too. No BBA, or any other type of algae that I can see aside from a light dusting of GDA after 1.5 weeks of no water changes. fish and shrimp seem happier/more active, too. I wish there was an explanation as to why my plants perked up from less gas. I was injecting almost twice as much as I am now, and the growth rates are half as much.
     
  15. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Might be from improved CO2 retention also.
    I know Gerry's tank had several enhancements there.
    That said, hair grass is not a demanding plant for CO2.
    Which is a good reason why it works well.

    But that's the idea, start high and then reduce. Not so high you gas the fish though!!!
     
  16. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,692
    Likes Received:
    720
    Local Time:
    11:38 PM
    Might be from improved CO2 retention also.
    I know Gerry's tank had several enhancements there.
    That said, hair grass is not a demanding plant for CO2.
    Which is a good reason why it works well.

    But that's the idea, start high and then reduce. Not so high you gas the fish though!!!
     
  17. Matt F.

    Matt F. Lifetime Charter Member
    Lifetime Member

    Joined:
    May 30, 2009
    Messages:
    2,319
    Likes Received:
    4
    Local Time:
    11:38 PM
    I know Gerry and I have different diffusion methods, but I can't help but think that the injection rate has something to do with how long it takes the CO2 to degas. A higher rate of injection, means more degassing since the bubbles are forced out of the ceramic disk with more force towards the surface. With a slower rate, the gas has more of an opportunity to mingle and circulate with the water. Does this seem plausible?


     
  18. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    Matt,

    I have been reducing c02 rate via NV adjustments and now the lowering of the PSI. So far I see only improvements as you do. Much lower rate and better growth/color by far Both smaller tanks have done BETTER in plant growth since the reduction.

    I also wish I could make some sort of direct correlation, but I cannot :)

    - - - Updated - - -

    Matt,

    I have been reducing c02 rate via NV adjustments and now the lowering of the PSI. So far I see only improvements as you do. Both smaller tanks have done BETTER in plant growth since the reduction.

    I also wish I could make some sort of direct correlation, but I cannot :)
     
    #18 Gerryd, Jan 2, 2014
    Last edited by a moderator: Jan 2, 2014
  19. Gerryd

    Gerryd Plant Guru Team
    Lifetime Member

    Joined:
    Sep 23, 2007
    Messages:
    5,624
    Likes Received:
    20
    Local Time:
    11:38 PM
    Hey Tom,

    As far as improved c02 retention please note that the 57 has had NO changes other than a reduction in c02 rate and this tank has had the most dramatic improvement in plant growth :)

    I did change to a sump and wet/dy on the 75, but c02 reduction had been underway for weeks already and the tank showed plant improvement PRIOR to the filter swap.

    I completely agree that the lowering of the 220 rate is a simple adjustment to match the tank's need, but boy what an adjustment!

    The funny thing is the fish had NOT seem much stressed at all. No hiding, fish are breeding, etc. But, in the 220 now I notice there is very little behavioral difference in the cardinal shoal whether c02 is on or off. I think this is great.

    So, we will see. I will do some ph readings and such, but I know that I had been trying to drop approx. 1 full ph point per tank. Any more than that and the fish WOULD be stressed.

    Very interesting stuff!

    Thanks!
     
  20. fablau

    fablau rotalabutterfly.com
    Staff Member Moderator

    Joined:
    Sep 13, 2008
    Messages:
    2,894
    Likes Received:
    624
    Local Time:
    3:38 PM
    Gerry, Matt, could you please tell us your light setup and light time?

    Matt: I am specifically interested in your 75gl wet/dry filter since I have your exact configuration and I am having Co2 issues right now. I am slowly increasing Co2, but I am already over 5bps...

    Thanks!
     
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