大家好。I've been searching for a discription of the hanzi used in the HSK tests.
If I finish RTK 3 and memorise the remaining characters on this website then should I be able to take level 4? That would probably be 3500 characters. How many characters do you need for level 5? All I kind find our descriptions about the vocabulary needed. (What does 1200 words mean? That doesn't seem like a lot.)
http://www.zein.se/patrick/3000char.html

(I don't mind if the hanzi requirement comes from the old test or the new test.)
谢谢！

I'd recommend you look through vocabulary lists and focus on words rather than characters because if you don't know the words then no amount of character knowledge will save you from a dismal score You'll also have the added benefit of testing your character knowledge as well while going through the HSK word lists.

For reference, 1033 words & 800 characters were required for the old HSK Basic level, compared to 8840 words & 2865 characters for the old HSK advanced level. Just to give you some perspective.

You can find the HSK vocabulary lists here