pico reefs have a hidden secret, they do not follow the gallonage/dilution rules of the normal evaporating tanks. they're easier to run. they break every rule written about reefing before 2001. since we usually don't stock fish but fancy corals, and a few easy inverts (which our systems can digest if they die/documented many times) there aren't really losses that happen over weekends or long holidays when we travel...large tankers can lose a single fishor two in some setups, and the resulting cascade is total loss.
they tolerate no physical external insults to the mad inverse; such as nerf, or an errant elbow, or breathing on them too hard. but chemically and biologically they're easier to run than larger reefs, going fully against the rules and norms of the last few decades agreed, solely because we have total reset control over the water column in an instant. Whats the solution for phosphate and nitrate issues in a 300 gallon reef? sixteen months experimentation, endless purchases of media, overstripping, understripping, all because we can't just rip change all the water
a pico reef's grandest biological and chemical problems are fixed in one fell swoop. Got a cruddy sandbed, clouding all the time, the seat of your nitrate issues in a pico reef? One hour rip cleaning, perfectly new sand, skip cycle, so easy.
end of nitrate issues
how many fail points does a 300 gallon reef have mechanically? ever seen people going on vacation and not worrying about the setups or buying massive $$ redundancies so they can sustain a few hours power outage? Imagine 7-10 days without topoff, and no external fail points other than your home AC in the summer, or your home heater in the winter, which kills all sized reefs anyway. a bait box bubbler will run your vase in a power outage for three days, two D batteries.
A bubbling airstone setup usually never fails, Ive never had one fail in 30 yrs aquarium keeping though I know threads abound with instances.
We have a thread here on why its easier to grow pro sps frags in a fishbowl than it is in an sps reef, bc it is, and the proof is shocking
now that's not to say that large reefs don't get the good fish, they do. They have dilution which in the event of tank loss clearly gives padding a tiny pico reef would be killed by involving fish loss events...but don't let those comparisons imply a vase isn't an ideal first reef or second reef, it sure is. Ive converted many away from large tanking heh its fun thing to do.
a pico reef that is square and has no special lid design or evaporation control meets all the requirements for concern and gallonage.
pico reefs have such little variance from predictable maturation phases, in one writing we can guide a complete SW newb how to run them for years. its currently going down that way at nano-reef.com, some first time pico reefers now have tanks of the month