Today im going to make some suggestions for stocking a nano tank so that it is interesting, colourful and most importantly sustainable!

Anyone who knows much about keeping a nano tank (that is a tank whose volume is less than 20 gallons) would know about the crucial importance of setting it up and stocking it without incurring any of the 3 big “O’s” that is; Overstocking, Overfeeding and Overcrowding. For continued success each of these needs to be avoided!

Banggai CardinalfishMany people simply can’t resist “just adding one more” fish or other marine critter who’s presence will tip the sensitive balance between stable water chemistry and system crash! This happens fast and can often be irreversible in such a tiny environment. If you are one of these people; stick to a bigger tank!

Here are some of my tips to help you have a sustainable nano system that thrives for the long term:

  • Use a protein skimmer! Other than removing dissolved organics it oxygenates the water.
  • Keep a clean-up crew, which will consume excess algae, detritus and uneaten food (reef safe hermit crabs, snails and shrimp are best) A good rule of thumb is to provide 1 snail per 2 gallons, 1 hermit crab per 3 gallons of water and 1 larger crab species such as the Emerald or Sally Lightfoot crab per Nano aquarium. Shrimp such as the Skunk cleaner and Blood red fire shrimp will feed off detritus and remove any parasites; double bonus!
  • Aim to have at least 1.5 pounds of live rock/live sand for every one gallon of your tanks volume.
  • Stock wisely according to a written plan; only make marine life purchases off this plan!
  • Yellowtailed WrasseJust a few fish that are small bodied, not territorial and are less active/slow swimming (so need less food and produce less waste for the bio filter to process) are the best choices. Consider these fish varieties: Basslets, Blennies, Cardinals, Chromis, most Clownfish, some Damselfish, Dartfish, Gobies, Jawfish, Pseudochromis and some smaller Wrasse species.
  • Regular maintenance is paramount with a nano tank, even 1 day of unchecked water evaporation can lead to system crash. Water changes performed regularly in a small tank are key to their life-supporting ability (10 –15% per week). Water testing should be performed daily (temperature and salinity) and a few times a week (pH, nitrates, phosphates).
  • When selecting corals bear in mind that corals requiring intensive lighting (like SPS corals) will need lighting that may heat the tank water too much, so a chiller or fan will be needed if you don’t want to fry your marine life. LED lighting options are by far the best for stony corals in tiny tanks.
  • Also aggressive corals (such as LPS corals with sweeper tentacles) need to be avoided as they can maim and kill other invertebrates and fish easily in such a small tank.
  • Beware “complete” set-ups; many are pretty far from complete and come with cheap components, my advice is to set up the tank with quality equipment yourself, preferably equipment with a higher rating than your small tank to give you some margin for error! Areas that are lacking with complete set-ups are usually water movement, lighting or protein skimming.

So how can you stock your tiny tank sustainably but still have it be colourful, exotic and interesting?

Despite their diminutive size, you can still keep a surprising range of small fish, corals, invertebrates and live rock/sand in nano systems…

If you nano is going to be a reef tank then corals should be the focus with maybe one fish. Nanos that focus on fish will need much more maintenance and attention because of the relatively large amounts of organic waste produced, so choose small peaceful fish of the families listed above.

Want something different and unique?

Try these biotope ideas or come up with something new and novel:

  1. The classic Nemo: A Clownfish (or mated pair) and compatible anemone.
  2. Colourful soft corals (mushrooms, polyps, leathers are best for nanos) and a fish or shrimp for movement.
  3. A Harlequin shrimp mated pair (prepare to feed them on choc-chip starfish!).
  4. A “my pet rock” nano; simply a centre piece of interesting live rock then say an anemone or soft coral on opposite ends and something for movement.

I hope you enjoyed todays Saltwater Aquarium Advice blog :)