Is it safe to install an aftermarket cooler once a stock cooler has already been installed for 1-2 months? Plz give me the best cooler options too. I think the Hyper 212+ is ok but is there anything better? What about water cooling? How much will temp reads will I get with water cooling on load?
No, it won't. I used the stock cooler, the Corsair H50 and Hyper 212+ on my CPU. Just watch videos on how to remove thermal paste correctly, and how to apply thermal paste correctly and it will be fine.
Yeah, there are better coolers then the 212+, but they also come at a higher price. Honestly, the 212+ is a great cooler and I got mine brand new for like 20bucks so it was a great deal.
By water cooling, I'm assuming you mean coolers like the H50? Honestly, I'm getting better temps on my 4.25 1090T CPU on my 212+ with the push-pull method then the H50. But, there are better CPU water cooling then the H50 out there, the price for it is pretty high though. If you aren't trying to max out your 2600k, air cooling is fine.
Currently on 4.2Ghz getting 53C on load using Prime95 on 212+