What is the minimum amount of sperm for conception?

Whilst in theory, yes, it takes just one sperm, a man usually has a count of around 100-300 million sperm, and only about 200 every make it to the egg, so obviously the vast majority never get anywhere near that. 33 million is a little low but it's certainly possible to conceive with this number, and 26% normal is good (most sperm is either dead or abmormal). Have every other day to allow his count to build up, rather than every day.