is my kh too high for my co2???

If you can bring the pH down to about 7.2-7.3 using CO2, I think that'll be enough for the tank. A higher KH just needs more CO2 to bring it down, if your using DIY CO2, just add another bottle or change the recipe, if pressurized, just turn it up. 7.5-7.8pH according to the charts, is giving you less than 10ppm of CO2. You could use RO water to bring the KH down, but it's easier to do it with CO2. HTH
 
If your willing to pay to lower your KH, then you could buy RO water, or an RO unit also you could buy a pressurized CO2 system. They're all more expensive than fiddling with your DIY CO2.
 
How big is this tank?!?!

4 bottles for CO2 seems like a lot!! What is your method of absorbsion? I have one bottle with a KH of about 10 that is giving me about 25ppm of CO2.
 
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