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diy CO2 vs KH and ph

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Well I just spent an hour providing background information since I haven't been in the planted tank scene for almost a decade. O started in College, had to drop it, and restarted a few months ago. I am trying to put together a cheap diy ten gallon to hold extra plants, but my diy CO2 system is failing.

The tank KH is similar to the tap water, which is 6° or around 100ppm (?)
The pH is also high- 8
If I use the CO2 table, those numbers mean I have practically no CO2, and would need a blimp full of CO2 plus a industrial reactor to actually lower the pH and have it bioavailable to plants. I recently brewed a sugar/yeast/baking soda mix using a 20oz bottle. (I cut the proportions Properly, I hope)
The unit is clearly producing CO2, and I built a nice little reactor, but when I test the ph after a full day of running the reactor, it doesn't change from the no-co2 morning level.. I'm still trying to understand the pH/KH relationship to CO2. For instance, if i we're to Increase bioload and have a good colony of nitrate forming bacteria, this is supposed to drop the pH. If you plug the new pH number into the chart, you suddenly have more CO2 in the water.
Also, if I somehow decreased the KH(maybe with a chemical additive or peat moss or whatever, that would also increase my CO2 levels, according to the chart. So I'm not sure if my CO2 setup simply isn't enough to make a difference, or if I should focus on and KH, which could result in a noticeable difference in CO2 levels. (Adding CO2 to soft water should easily swing the ph down, but with a higher KH, the CO2 wouldn't effect the pH nearly as much. So what should I do? And how can I naturally lower KH?
-Would adding diy CO2,which for me produces maybe one bubble every couple seconds (BUT is hooked up to a very efficient diy reactor) cause an appreciable improvement in plant growth, even if the pH values don't lower as a result? Or is CO2 totally useless.given a high KH and pH? I suppose the KH and pH values dictate how helpful CO2 is. Help!
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Just put the ph/kh table out of your head as they don't work very well in the aquarium hobby. The table works in the absence of phosphates which tap has as well as fish food and ferts. Go off of ph drop. I just set up a diy system on my 15 using a one liter bottle with 2 cups of sugar and one packet of yeast and after 12 hours got a 1.0ph drop. I'm also getting a little over one bubble per second with standard black co2 tubing. My setup only last about a week so you could do a two bottle setup and change one weekly and alternate for better co2 consistency.

And obviously make sure your ph readings are accurate.

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