Help! I need a diy co2 recipe that WORKS!

Carissa

Guru Class Expert
Jun 8, 2007
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I just found this on the Krib...

"Also, most KH test kits actually measure total alkalinity. If KH is the predominate component of alkalinity, all is well. However, if other buffers are in the water (phosphate buffering products, for example), you will get a higher "KH" reading and you will think you have more CO2 than you really have."

If this is the only issue with the accuracy of the table...it's not an issue for me, because since my tap water KH is 0, I know that all KH in my water is only from what I've added, namely, the baking soda.
 

VaughnH

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Jan 24, 2005
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The other half of that statement is that all of the acidity in the water must come from CO2, so tannins will also throw off the KH/pH/ppmCO2 relationship.
 

Carissa

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Jun 8, 2007
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Ok that makes sense. So lets say I have tannins coming out of the tap, but I know my tank water is 8.0 before adding CO2 and there are no tannins leaching into the tank from driftwood or anything. Would that make a difference? i.e. would a drop of lets say 1.0 pH always mean x amount of CO2 was added (if nothing else were added to make it drop)?
 

VaughnH

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The drop of 1.0 in pH means that the amount of CO2 in the tank is 10 times as much at the lower pH as at the higher pH, assuming nothing else changes in the water except for CO2 coming out of solution. The problem is that you still don't know what the ppm of CO2 is at the high pH, so you don't know what it is at the low pH. It could be .5 ppm, 3 ppm, 10 ppm, etc. which would mean 5, 30, 100 ppm at the low pH. That isn't too helpful.
 

peterh

Junior Poster
Jan 3, 2007
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Hamburg, Germany
Hi,

I saw, that some of you are changing bottles every week so I want to explain my approach (which gives me beyond 3 weeks).

I run a 5 liter bottle on a 60g with active diffusor.
On the net (krib?) is a very detailed english article about dry yeast which I am following:
I take a cup of cold water (Kh10), put a bit sugar in and let it rest a while to solve oxygen. Then I put about half a packet dry yeast (5gr?) in and stir. After a couple of hours, the yeast starts to work and some foam forms.

By that time I have solved about 500gr sugar in 4,8L water (room temperature). Then I put the yeast in but not the foam.

That's it. I guess, many people use too much dry yeast or use too high temperatures. More sugar should be possible, but I think the yeast does not survive much longer anyway.
Probably, I could also go with less yeast. But the large water volume in the bottle takes a lot CO2 initially, before pressure builds up towards the tank. And I don't want to wait that long...

Bye,
Peter
 

nwfishinfool

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Jun 22, 2007
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Hi Peter,

I'm one of the weekly bottle changers. I'm curious, can your CO2 set-up keep your water saturated with a sufficient (approx 30ppm) CO2 level over the entire 3 week period?

My mixtures haven't stopped producing at the end of the week. I just want to make sure my CO2 levels don't drop and I get into an unbalanced situation with my lighting, fertilization and CO2 levels. I can keep a consistent 30ppm in my water by mixing a new bottle every week. I'm probably a little paranoid, I battled algae issues until I stabilibized my CO2 and fertilizer dosing!

Mike
 

peterh

Junior Poster
Jan 3, 2007
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Hamburg, Germany
Hi!

nwfishinfool;19016 said:
I'm probably a little paranoid, I battled algae issues until I stabilibized my CO2 and fertilizer dosing!
Mike

Yes, maybe. I do check the tank's pH towards the end of the bottle, but I have never noticed a sudden drop. Also, I can count the large bubbles in my DIY venturi every two days so I notice when production slows down.

The saturation? Hmm. As I don't have a CO2 test, I checked only kh and pH. Based on that I should have about 20mg average. I stop the venturi at night and 3hs around lunchtime. I got rid of the dust algae when I got the phosphates right. Tank is now very clean.

Peter
 

Carissa

Guru Class Expert
Jun 8, 2007
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I got rid of the dust algae when I got the phosphates right.

I'm curious to know what you had to do with the phosphates. I have a bit of an outbreak of gsa in one tank, I tried increasing phosphate in both my tanks (one to get rid of it and the other as preventative), and this only seemed to make it worse and now I have gsa in both tanks. Although perhaps gsa and gda are quite different.

What I'm doing now with my co2 is dumping out half of the water in one bottle each week, replacing it with 1/2 c sugar and traces and more water. This is keeping my yeast alive and I don't need to add any more yeast. I'm thinking about trying brewer's yeast, not sure if this will work better or not. I need some larger bottles too, a 5L bottle would be easier to maintain than the 2 bottles i have now.
 

peterh

Junior Poster
Jan 3, 2007
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Hamburg, Germany
Hi,

quite simple: The dust algae disappeared within two days after I raised PO4 from 0,25 to 0,75-1,0. Nitrate is around 10.
Before, every time I added Nitrate, the GSA would start to grow on the glass. Now the snails have cleaned all the old GSA and I don't see any new growth. Everything looks quite shiny.

Peter
 

peterh

Junior Poster
Jan 3, 2007
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Hamburg, Germany
Hi,

a correction to my earlier post: I weighted one of my dry yeast packets today: About 7gr. So I use about 3,5 gr on 5L suger water. And that is still plenty.

Peter