So, for my own edification:
Sump w/filter sock; macro, live rock, DSB and other stuff (semiDT) refuge; Siporax section; Skimmer, Bio-pellet reactor in the return section. Then,
CalRx, Sulphur denitrator and GFO reactor-to-a-carbon reactor, fed from return section area and a heater there (that I wonder if it works [have titanium replacement (*to do)]) and return pump feeds to chiller that feeds through SQWD (that pretty much does not work [have replacement (*to do)]) to two return nozzles.
All ran through APEX classic gold with an extra EB8.
Still left/want to do:
Remove all or most of the black sand
Poss. add sand pan to one area of the tank
Possibly add more sand to DSB area of refuge
Add Kalkwasser Reactor (have this)
Replace two lights with upgraded lights (still need to acquire)
Add another light to macro refuge (have this)
Add 5-channel doser (have this) and mini fridge (don't have this)
Add more cameras (don't have this)
Add another (at least) EB8
Add leak detection
Add more sealer to top rim of tank to prevent salt creep in corners
Replace return bulkheads with strong schedule 80 slipxslip ones.
And wish-list but most probably not doable:
Pipe water station to tank.