Do you really need Chemical Filtration in your Filtration System??? Such as Chemi-Pure, Nitra-zorb, Ammonia Chips??? Isnt your biological System suppose to take care of those? Just askin cause i was told the more BB the better and that Chemical Filtration Is a waste of time and money... Bought a 40oz bottle of Chemi-Pure for my DIY Filter But would Like to add more BB Media But if i do the lid will not close w/ the Chemical Filtraion on top of the BB Media... What Should I do??? Cut out the Chemical Filtraion and add more BB Filtration Media or Split the difference of both medias... The tanks is going to house 6 Catfish till the grow out to a decent size then move to a bigger tank...