I really like the style you are going for. More busy bee's you have to get the work done for you like turning the sand bed freeing hydrogen sulfide over time. The critters eat the detritus. Also leaning more then most people well ever need to know about population control of types of out breaks that may happen and what to do about it, when there dip and quarantine didn't work out.
Please post more of your system~ I like it.