Aged, hands-off sandbeds are among the greater liabilities that develop as the years go by, there's an unconsidered pathway where they are indeed the breakpoint in a full system crash or not-
power outages.
side by side, I bet a given 2x aquarium test using a 5+yr aged/nonrinsed sandbed running with fish, alongside a bare bottomed tank with even a few more fish but adequate surface area inside, will reveal the BB lasting longer during simulation due to much less biological oxygen demand. A sandbed presents an oxygen sink far greater than the tank's swimming bioload I bet, with increased command coming with increased organic waste levels, a mixed heterotroph's ideal campground. Detritus storage equals unneeded o2 robbing during a highly sensitive time
most are having to dose vodka anyway to systems that employ used DSB's, and BB crews show they're not critical in coral growth. rethink the old sandbed.
That's not to say twenty readers right now aren't doing fine with the core sandbed approach which is employ and house/feed the most diversity possible. Its to say their tank wont beat a BB setup with even a slightly higher bioload during a simulation test, I bet. time w tell, someone might eventually run the experiment.
A new sandbed or a highly rinsed/clean one presents little extra BOD command even though the surface area is still great, due to absence of the high organic portion which is the turbo fuel for bacteria that consume oxygen. my tank is out to 12 yrs old due to not storing detritus, and having backup bubblers handy for power outages. Its also handy to have cheap 20$
amazon fishkams on the system to monitor by cellphone from afar.
a couple of $20
amazon smart ac outlets, and you have a cheap way to intercept issues when on travel. handy for those without the fancy internet controllers. handy as actual backup to those, bubbles on command.
merely being able to shut your tank lights off remotely is a cheap and powerful coral saver too.