I am outside of Clayton city some I am on Johnston County water. Anyone know if water here is OK for planted tank? I am setting up a new 265 gallon tank and wondering if it will be OK or if I will need RO unit.
It might be worth running a few tests or taking a sample to your LFS to see what your tap runs.
TDS (Total dissolved solids) - Should read less than 250 ppm.
GH (general hardness) - Basically calcium + magnesium, should be around 7 dGH.
KH (carbonate hardness) - Buffering ions, should be less than 6 dKH.
These numbers are very general and could be different for particular species. You could also run a pH and ammonia test (can indicate chloramine, which I saw in the report) or even send a sample in to an analysis lab. If you use the tap for your tank make sure you use a dechlorinator that works on chloramines and chlorine. If you go with RODI make sure the unit is made for chlorine or the membrane will be damaged easily.
Johnson Co's raw water comes from the Neuse River, so it's presumably similar to Raleigh's water. Hardness (GH) and Alkalinity (KH) are not listed on that water report link, but I'd guess they'll both be around 30 to 40 mg/L, or 2 to 3 dGH and dKH. The high pH (8.3) at the tap is probably from a corrosion-inhibitor added at the treatment plant, and doesn't necessarily mean high KH. Should be fine for a planted tank.