The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Diatom is not bad! It flourishes when there's silicate in the water(which is mostly found in new setup), so it will go away once silicate is depleted. If you can wait for it to go away by itself, then the best fish to get will be otocinclus. They will eradicate diatoms in a few days.
Ignore diatoms and they will go away eventually. I think buying a fish to rid a problem that sorts itself out doesn't make sense , unless you wanted one of that species already.