Tank sizes---and shapes.

Sk8r

Staff member
RC Mod
Discussion is invited.
For fish---long is generally better.
For corals---because coral-capable lights are expensive---cube or wedge is nice. Note: stony coral (skeleton) needs fancier lights than softies, plus calcium supplementation: this is not hard, but must be done. They eat it.

10-20 gallons---small softie reef. Invertebrates like shrimp. Eventually (they're fragile fish) smallest gobies, esp the littlest shrimp-gobies.
30 gallons---much the same as 10, but 1 dartfish is ok, slightly larger gobies, small blennies are good. Pearly jawfish if you have fairly deep sand. Royal gramma, or chalk basslet. THat's a selection menu, not a 'get them all!'
40---much the same, but multiple gobies are ok: some blennies don't like their own kind.
50---1 damsel, 1 dwarf angel, 1 dartfish, plus previous others, or small clowns with, after 6 months, nem. If you go for larger species clowns, they need the whole tank, and other fish are at risk. This size tank is good for specialty fish like full-sized lionfish, or others like eels, etc, that may need both room and a lack of roommates.
75--- additional gobies, but still only singles of those in the 50 list.
100---1 damsel of a kind, up to 5. Cardinals, dartfish, one of the very small tangs (tomini, eg), all of above.
120---better for tangs than a 100, but stick to very quiet grazers like kole. All of above. Go long tank for tangs and anthias. Rabbit is ok, but will get large fast.
150--More of same, and for tangs and other 'running' fish, the longer and more water the better.
300-500 A lot of oxygenation is helpful for tangs, big angels, butterflies, and others that are appropriate for a large tank...the little guys can live in the cracks, if not on the menu, and some fish like damsels and anthias will occasionally school-up. Very few novices start with mega-tanks: we all wish, eh? But they're quite a bit of work.

If you have fights or aggression, very probably you're overstocked, or you have a tank dominant: once a dominant gets established, this requires some fish-handling skill to get a new guy in.
 
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I started out again about 4 years ago with a 36" long, 56 gal tank after having a 125 gal 6' tank in the 90's. I had a 6-line, 2 clowns, an orange spot goby, and a 2 1/2" tomini. After the Tomini was about 4" long, it became necessary to get a bigger tank, not because of aggression, it was just clear he needed more swimming room so I stepped up to a 4'x2'x2', 120gal. I can see that having a longer tank is the main consideration for the length of a fish but having a 2' width rather then an 18" really opens up a lot more space to provide hiding places for each fish when arranging rock. Next year when I step up to a 6' tank, I'll def. get one thats 2' front to back rather then 18". It really surprised me how much easier it was to both aquascape and provide good circulation around the rock with the extra 6".
 
Good point, that. They have to have room to maneuver, and rockwork 'folds' space in ways that many critters can use.
 
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