drawbacks with pressurized CO2?

[skratikans]

ok...so when using pressurized CO2 how does one control the pH ..my tanks now have a steady pH of around 7.4 thanks to a nice bicarbonate buffering system with my eco complete...without the pressurized CO2 this system with stay for around 5yrs or so...with pressurized CO2 the buffer system will deteriorate in 1-2yrs and thats when the pH will no longer hold spike in acidity..right? and the only way to go around this is to add baking soda?...Can you buy calcium bicarbonate rocks online? Or is changing out the substrate every two years a must? Anyone experience this problem after two years of pressurized CO2 use in their tanks? Any tips?

[fishgeek]

your should be replacing buffering with your regular water changes

dependant on your tap/source water alkalinity you may not need to worry about this at all
if you have very soft water then you may wish to add buffer, calcium carbonate, phoshphates in some fashion... coral sand is an option... to a water storage butt in which you can test the water and then mix with further tap to acheive what you wish before adding to tank

andrew