hmmm.....ammonia and nitrite toxicity, or nitrate haven???? How about neither....do your maintenence and water changes and there really shouldn't be issues....I think that is reddrums entire point.....I agree, do your maintenence and water changes on whatever filtration device/bedia you choose, and most problems with the nitrogen cycle can be alleviated/reduced......if you use bio balls, siphon out the compartment they sit in from time to time (just keep them wet).......

maitenence....