Sustainable aquarium enqiury

Question
Dear Paul,
My name is Lauren Roman and I am a university student studying ecology. At uni, I am currently doing some lab work in the coral reef ecology lab for one of my subjects, and the head researcher wants to set up a 'self sustaining' (not a closed system, but ecologically stable, eg, fish and shrimps take care of algae, clam / sponge filtration to supplement filters etc) fish tank. She has bought a very large fish tank to set up in, but wants to know what species are good species to have in such a fish tank. I was wondering if you could possibly recommend some marine species that have key ecological roles and would go well in a 'self sustaining' marine aquarium. She was also interested in getting a baby epaulette or other small shark to put in the tank, but wasn't quite sure whether or not this was practical. The tank size is 750 x 750 x 1400 mm. Any advice or recommendations would be greatly appreciated.
Many thanks,
Lauren


Answer
hi, sounds like an interesting project. unfortunatly it is impossible to have a self sustaining reef, you will always need to do water changes on the system, this exports nasties (mainly nitrate loaded water) the tank size is pretty small when it comes to a low maintenance reef, the bigger the tank the easyer it is to maintain. it means that the nasties are more diluted and makes them less harmfull to the inhabitants.

i take it you know about live rock and tank cycling process? if not thats your first port of call for reserch. also its absolutely out of the question to get a shark, for starters you would need a tank roughly 4 times the size of the one you have, and secondly they would be wild caught (as are 99% of marine fauna offered for sale) i also dout it would feed, there are basically some things that are not meant to be kept in captivity.

as far as species that have key ecological roles, have a look into algae grazers such as hermit crabs, snails, sea cucumbers, tangs, rabbit fish and angel fish

cleaner shrimp, blood shrimp, coral banded shrimp, cleaner wrasse, neon gobies generally take care of the fish cleaning.

may also be worth looking at the symbiotic relationships between some marine fauna, it is truly amazing how some of these creatures benefit from each other.

would you mind running me step by step through everything you have done, that way i may be able to tell you if you have missed something or perhaps a better way to do something.