Decreasing c02 - observations

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.

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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!

 

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.

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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.

 

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.

 

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.

 

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

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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

 

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!