Newbie here.. I’ve been cycling for two months now w 100 gallon tank, 20 gal sump. Ammonia went down in about two weeks. Nitrites went up to 2.0ppm and now nitrates are 30ppm. I have had 2 clowns since week 2. I have a YWG doing fine since two weeks ago. Is it normal for my nitrates to still have not budged? Can I add a snail or some bangai Cardinals?