MARINE AQUARIA
On and off during the past 20 years my family has maintained a ~60 liter cold salt water aquarium. We live near the sea, so it's not difficult to occasionally refresh the water, nor to find new seaweeds and creatures to put in it, mostly collected from rockpools and the beach. Fish require feeding, which adds to the nutrient load in the tank, and although the sand filter generally keeps up with this (and worms living in the sand flourish on it) the tank usually only contains a few small fish. We've generally found other creatures of more interest, and more likely to survive - crustaceans, mollusks, echinoderms, marine worms, anemones etc.. The snapping shrimp photo in my hydrophone pages was of one that survived for over two years in the tank.. Here are a couple of the more interesting specimens from this year:
These
beautiful but fragile slugs Glaucus Blue Sea Slugs (above left) are
washed up in large numbers on Avalon beach during strong onshore weather in late
summer, together with Janthina Sea Snails (below - note barnacles attached), and
millions of blue-bottles and By-the-lee sailors. The Janthina suspends itself
from a raft of bubbles. Neither survives long in the aquarium, but perhaps they
are already injured in some way by being washed ashore through the surf.
On the practical side one of the problems we've had over the years has been local power failures, causing the circulating pump to stop, which apart from stopping aeration, removes the suction pressure that holds detritus within the bottom sand filter. The result is a rapidly fouling tank and dead creatures. Such blackouts have become much less common, but a solution is to fit an uninterruptable power supply (the sort sold for home PC use). Another approach might be to run the pump from a car booster battery and a small inverter (some boosters have inverters inbuilt) , which could be kept charged from the AC supply. If necessary this should run a tiny air pump for days.