What are the differences between Non-O and Non-OA visas in Thailand, and why did my stay duration change after re-entry?

I thought that with the Non O A you still need to show funds in Thai bank , just not at the beginning . I thought once you enter the country and start your visa , you then need to put 0 baht in Thai bank so that it is seasoned by the time you get the extension after 90 days.

Have I got this totally wrong ?

@Craig *******

It mainly depends on whether you want to tie up 800k baht (almost untouchable) in a Thai bank account earning about 0.5% interest, or commit to transferring 65k baht per month from overseas (the better option of these two as you can spend every baht of the 65k as soon as it's registered in your account) OR whether you want to demonstrate money in an overseas account (usually equivalent to 800k) earning a much higher interest rate (in my case I use Supernannustion funds earning around 7% tax free). The money I make from the super fund so very easily covers the cost of a decent health insurance policy, which is a requirement of the OA. Once the original 12-month VISA (not the entry stamp) is almost at expiry you step over a land border, step back in and get a further 12 month stamp (no need to visit an immigration office to beg for an extension). At some stage during the period of that entry stamp (the later the better) you fly back home, spend a bit of time with family and friends, apply for a new OA and repeat the process. You transfer only as much money as you need, and never have to visit a dreaded immigration office. You get two years from the one visa