I've been experimenting with various 'recipes' for DIY CO2, and could use some input. As a side note... the fish have been removed from this tank to avoid adverse issues related to the pH crashes that have been inevitable.
My current tap water conditions are:
GH: 9 degrees
KH: 5 degrees
pH: 7.4
Calculated CO2: 6 ppm
The tank is a 20H
estimated water volume minus gravel, driftwood,rock: 17 gallons
The recipe that has provided the greatest CO2 yields to date has been one that I never thought would work:
- 3/4 cup cane sugar dissolved in 2 cups hot water
- 1 teaspoon Fleishman's Active Dry Yeast - dissolved in 1 cup cool water
- I immediately add the yeast mixture to the sugar mixture
- add 3 more cups of room temperature water to the bottle until it's full to the 'shoulder' of the bottle
- leave the bottle open for ~2 hours
- hook it up to the airstone in the intake of my HOB filter
It yields:
pH: ~6.6
Calculated CO2: 38 ppm
Which is lovely... plants are pearling like crazy.
BUT!! the mixture only lasts 4 days before the pH begins to rise again. At this point I've been changing the mixture to avoid the 2 day crash back to 7.4.
I've tried numerous other recipes that have involved much more careful preparation of the mixture.... boiling the water prior to mixing the sugar.. allowing the yeast to warm to room temperature before adding ~104 degree water.. adding a pinch of sugar to the yeast prior to adding it to the mixture to "activate" it... and allowing ample time for the yeast to hydrate before mixing. I've tried less water, more sugar, less yeast.... quite a few combinations... None of these techniques have produced a mixture that has brought my CO2 concentration to anything above ~20-25 ppm... and none have worked for more than a day or two.
I'd like to obtain a recipe that will allow me to see a CO2 concentration in the 30-40 ppm range (the fish don't seem to mind this level in the least) and more importantly, I'd like it to last for at least a week.
Any suggestions?
My current tap water conditions are:
GH: 9 degrees
KH: 5 degrees
pH: 7.4
Calculated CO2: 6 ppm
The tank is a 20H
estimated water volume minus gravel, driftwood,rock: 17 gallons
The recipe that has provided the greatest CO2 yields to date has been one that I never thought would work:
- 3/4 cup cane sugar dissolved in 2 cups hot water
- 1 teaspoon Fleishman's Active Dry Yeast - dissolved in 1 cup cool water
- I immediately add the yeast mixture to the sugar mixture
- add 3 more cups of room temperature water to the bottle until it's full to the 'shoulder' of the bottle
- leave the bottle open for ~2 hours
- hook it up to the airstone in the intake of my HOB filter
It yields:
pH: ~6.6
Calculated CO2: 38 ppm
Which is lovely... plants are pearling like crazy.
BUT!! the mixture only lasts 4 days before the pH begins to rise again. At this point I've been changing the mixture to avoid the 2 day crash back to 7.4.
I've tried numerous other recipes that have involved much more careful preparation of the mixture.... boiling the water prior to mixing the sugar.. allowing the yeast to warm to room temperature before adding ~104 degree water.. adding a pinch of sugar to the yeast prior to adding it to the mixture to "activate" it... and allowing ample time for the yeast to hydrate before mixing. I've tried less water, more sugar, less yeast.... quite a few combinations... None of these techniques have produced a mixture that has brought my CO2 concentration to anything above ~20-25 ppm... and none have worked for more than a day or two.
I'd like to obtain a recipe that will allow me to see a CO2 concentration in the 30-40 ppm range (the fish don't seem to mind this level in the least) and more importantly, I'd like it to last for at least a week.
Any suggestions?
