The idea of a nano reef is that it is small ..... so the number of fish and the size of the fish should be small also. how small ? well that depends on how small the aquarium is. Nano reefs and be as large as 25 or 30 gallons or as small as 2 gallons. having said that.. the number of fish and size would be determined by the size of the tank. Avery small tank might only have 1 tiny fish or a few small shrimps . A little larger tank might have 2 fish or inverts and so on. The following fish are just a few of the fish that are small enough for the nano reef and one key note is that most of them stay small ! Just because you see a tiny fish that does not mean that it will remain that way so unless you have a larger tank to move them to when they become too large, then be sure to check on their expected full size.
Very tiny fish that will remain small for the tiny aquarium
Citron Goby
Blue neon goby
green clown goby
Yellow clown goby
gold neon goby
Hi-fin goby
Paddle fin goby ( best kept in pairs)
Red headed goby
Fish for the 12 to 20 gallon or larger nano reef
(can be a single fish in a smaller tank)
Algae Blenny (lawnmower blenny)
Bi-color blenny
six line wrasse (good flat worn eater)
Fairy basslet
Yellow line basslet
Black cap basslet (expensive)
Fork tail blenny.
Canary Blenny
Red fire fish
Purple fire fish
Yellowheaded Jaw fish
Blue spotted Jawfish (very expensive)
Black widow blenny
Midas Blenny
Green mandrin dragonet
Spotted Mandrin Dragonet
Strawberry Basslet
Longnose Hawk fish
Bluespotted yellow watchman
Here are a few cautions to consider about the care and compatability of some of above fish
Dotybacks and basslets can be aggressive and should not placed with each other
Fire fish and Jawfish are known jumpers and need a top on the tank to keep them from jumping out
Mandrin Fish... 1 to a tank they do not get along unless paired male and female. Need a very established tank because they need a large amount of live copepods in their diet and do not take frozen or flake food well. Green spotteds seem a little easier to get to except prepared food.
Hawk fish very coral safe but... caution with shrimps and very small fish
