My intertidal invertebrates are from a relatively temperate climate, where the water is usually warm enough even for humans to swim. And, being intertidal critters, they tolerate a variable temperature. So with my previous tankful, I set it in an open window; the normal Lower Fraser Valley air temperatures would keep the water in an acceptable range.
But Val, my anemone from Campbell River, is another story. She likes it cold. An average of 56 degrees would be good for her.
Most saltwater aquarists invest in a chiller, a refrigerating unit that cools the water and returns it to the tank. Very nice, needing some maintenance, but what doesn't? But they are expensive! The cheapest is more than the total I've ever spent on the whole setup. And they go on up to over $1000, besides needing a cabinet and a bunch of fittings, making a racket, and being a general nuisance.
So I've gone with the freebie alternative. I've filled a bunch of little plastic cups with fresh aquarium water, and put them in the freezer. Every morning and evening, and several times during the day, I dump some of the saltwater ice in the tank, and refill the cups with aquarium water to go back into the freezer. It takes about 3 to 5 lumps of ice to bring the temperature down to where Val won't go into a sulk.
At first, I would put the ice into the water very carefully, because the hermits would startle at the noise of a splash. They're used to it now. They don't even mind when an ice chunk bumps into them when they're climbing on the eelgrass.
So yesterday, I had dropped in the first two lumps of ice. There were several hermits climbing the eelgrass; no problem. One of the larger hermits made a flying leap onto the ice. His own hermit-sized ice floe! This is living!
Too bad it was melting so quickly; his claws lost traction after a minute, and he slid off the side and tumbled down to the sand.
And, of course, I had my hands full of ice, and the camera on the other side of the room. So you'll just have to imagine it.
To make up for that, here are three more tank pics. No hermit polar bears, though.
|Another look at Val's column. She has pasted shells and stones and a lot of gunk all over it. If you look closely at the photo, you'll see an amphipod (bottom right) and, at full size, a number of copepods, some carrying eggs.|
|Just another Nassa snail, siphon extended, sniffing out his path.|
|Checking out a possible change of clothes. (He didn't go for it; didn't even try it on.)|
These hairy hermits are among the most drab of all the hermit crabs; a dull brownish green, darker antennae with white spots, black eyes, and a hint of blue at the knees. Or so it seemed. This camera does colours so much better! The blue knees are vivid, the carapace patterned in blue-green and gold. And I love the stripy eye stalks! I never noticed those before. (It's worth right-clicking to see this one full-size.)