You can't. Just wipe it down and prevent splashing. And depending on your water, it's alot worse saltwater, though I haven't kept a brackish tank in a couple of years, so perhaps I don't remember correctly.
i think a salt tank is worse. i just take and turn on the hot water and rinse everything good once a week. if you get thos streaks on the hood or glass of the hood that just wont come off use vinegar cleans it right up