30ppm CO2 (rusty brain)

[tranquillus]

Hi

I've had a planted tank before, with pressurized CO2. I've had a year and a half break from aquariums, and now moved to a new city.

I've measured the tap water here to be pH 7 and KH 11. From the pH/KH/CO2 relationship tables, it would appear that my tap water already contains around 30ppm CO2.

Am I correct in thinking this? (My brain feels a little rusty on these matters)

If this is correct, I guess I won't need to buy a CO2 injection kit for the new aquarium I'm going to be setting up?

Thanks