It'll be fine.
FWIW, I used a MJ 1200 in a 32g bucket for a while. Sometimes the salt would settle in one little part of the bucket, but you just have to shake the cord of the pump (up and down usually works) and it will redirection itself. This usually gets rid of the last bit of salt. I put a Seio 820 in my mixing bucket since I had an extra laying around, works just as well (still have dead spots)