Invert-Only Reef tanks

[Robotic Chimera]

Am I the only one who doesn't really plan on getting fish? I have a 55-gallon and hope to upgrade eventually to a 100g (not for a long while, obviously), but most of what I want is just shrimp, starfish, sea urchins, anemones, and a few corals.

There's fish I would love to have, such as puffers, but could never get one as they'd easily chew through my shrimp then grow too large for my tank. I like mandarin dragonets as they're small and colorful, but their specific dietary requirements would be too much for me. I still consider myself a beginner since my tank has only been up for almost a year now, i've avoided any major disasters so far.

Anyone else do non-fish "fish" tanks? If so, what kind of inverts did you like having?

Some of my personal favorites are blood red fire shrimp, tuxedo urchins, Scutus snails, and brittle starfish.

I think Tuxedo urchins are some of the most hilarious creatures though, I love hearing about what kind of silly things they pick up and wear as hats. One of mine picked up a shed shrimp exoskeleton and wore it around for a while, and another time one tried to wear a thermometer that got loose and was floating around. It put it down once it realized it couldn't descend with it.

I'm wondering if there's any interesting inverts I haven't heard of that could go well in my tank. Things like clams seem nice, but they're apparently very difficult to care for so that's out for now.

Though another thing i'm worried about, is how many inverts is a "good" number in a 55-gallon before things get "crowded"? There's not much info on how much of anything should be in a tank (other than fish), and i'm worried that at some point i'll hit a place where there might not be enough nutrients to support some everyone. I certainly don't want anyone to starve!
There isn't a ton of stuff in my tank currently but I don't have a ton of algae everywhere (excluding macroalgae) so i'm particularly concerned for the herbivores if I decide to add more eventually.

[Ron Reefman]

There is nothing wrong with your tank idea. I have 4 tanks, a 125g very mixed reef tank, a 55g cube display refugium with a red Hawaiian reef lobster, a couple of urchins, some emerald crabs and porcelain crabs. I have to be careful with what goes in this one as the lobster (named Hannibal... for obvious reasons) isn't too fond of tank mates. I have a 25g frag tank.

But along the lines of your tank, I have a 65g (4'x2'x14") shallow reef with mostly local stuff from the Gulf of Mexico and the Florida Keys that we collect ourselves (my wife & I). I do have a couple of things that I bought from Gulf Coast Ecosystems, KP Aquatics and TBS, but they are still local critters. Currently there is a juvenile Atlantic Blue Tang (it's yellow now in it's juvenile stage) for nuisance algae control and a Gulf Toad Fish which came with some local live rock. I also have a couple of different sea cucumbers, a couple of different urchins, rock flower anemones, curly-Q anemones, brittle and serpent sea stars, a mated pair of gold banded coral shrimp, 1 red and 1 white flame scallop, a 'soon to be too big' stone crab, some clams, rock oysters, limpets, chitons, snails, hermit crabs, emerald crabs, porcelain crabs, green and blue zoas from the Keys, several gorgonians, lots of small white feather dusters, and several different macro algae. I'm trying to get a sponge to survive in the tank, but they are extremely difficult to keep (other than the ones that grow under the rocks). I'd also like to try a bigger spaghetti worm from the Keys, but they are difficult to even transport from the Keys, 5 hours to home!

Is your tank a standard 55g (i.e. 4'x12"x21")? When you decide to go to a new tank, consider a bigger footprint but shallow. That makes a lot more room for sand and rock and therefore inverts. It's also a lot easier to work in. I have to harvest macro algae fairly regularly. I also have an old 125g acrylic tank in the stand that has a 15g refugium and lots of live rock and a big skimmer. I also run my 25g frag tank off the same sump/refugium.

Do you know about TBS (Tampa Bay Saltwater) live rock? I would not recommend them for a 'normal' reef tank as the rock has lots of 'extras' you may not want. But for an invert tank it could prove interesting. The toad fish I have came with some TBS live rock.

Do you have any anemones? Sea cucumbers? Emerald crabs?