About this water changing thing!
All filtering should be remote.
The last tank i built,i made a multi level plenum style bio filter,(three levels) to go with it.
An algae scrubbing environment that needed trimming once a week,it was based on complete water purifying methods,down to the type of algae,possition of algae and maintenence of the algae.
I did no water changes for one and a half years.
The prefiltering was a lot of work as was the maintenence of the algae.
Never added trace elements,the algae did that in it's converting of substances and the foods i used.
Except for a few other small polyp corals all the creatures in the tank did very well.
There were,tangs,surgeons,angelfish,clowns,shrimp,anemonies,coarlimorphs,tube worms,gonie,finger coral,stag aropora,plate acroporas,and a lot of other species.
It was a three foot tank,now i have four of a similar size and one alage environment and a wet section runs all of them.
If you want to not do water changes on the tank that is described on this thread,it will slowly but surely do badly.
By the time you realise the creatures are suffering,it will be to late for some of them.
Nitrate poisoning and other substance poisoning that will not show on a standard test will eventually take its toll.
The ocean remains quite good because of mainly phytoplankton(algae) and if something algae of a substantial amount and kept trimmed is not in your water, somewhere working hard,it will not work.
If you said you had a very well designed algae scrubber,along with other filtering methods,it may work!
There are so many misconceptions about algae,that it is quite sad.
Look at how important these tiny creatures are to us as they make a lot of the worlds oxygen and converts huge amounts of carbondioxide and produces silica,than there are the corals,coraline and anemonies in there symbiont relationships and these are only parts of what algae carries out.
Good luck,i always encourage people to experiment as i did for many years,because when you learn the hard way,you remember it!