do I need to buy reset codes after installing ink potty

Yes, you will have to due to how the counter is designed. As the printer expects it to be internal, the WIC count will always trip given enough time and usage even externally cleared. Epson counters are based on pages printed (in other words if you printed on 5% of the page, it burns 1 whole page off the counter; heavy jobs may burn 2 if it has to mid-purge on wide format printers doing a 11x17+ job). As such, the frequency of future resets varies based on how often you use the printer.

The days of not having the care about it for years (when it did, the printer was well past its prime like the R200) died in 2010 with the black series printers with the rear screw pad module due to weaker pads to do that (to add insult to injury they will not sell the pads or reset keys -_-. WTF was that move good for beyond stopping new 10+ year runners like the R200 which can do it?). That said even with the external ink tank, the print mech and printhead will eventually wear out; it may get 5, or as little as 2-3 if you really run it hard. I have seen some of these new Epsons die in 1-2 YEARS, or UNDER WARRANTY.