What is considered a Nano reef aquarium? How small is a nano reef aquarium? Is my tank to big to be a nano?

These are the questions you will always come across when reading a nano reef forum or any reef forum at that. I do not believe there is a definite answer to this, I do however personally feel that anything more 20 gallons is not a nano and 15 gallons is pushing it.

In my view, a true nano, in every sense of the word is up to 10-12 gallons (not including a sump).

Can a nano reef aquarium be as successful as larger tanks? Do I require a protein skimmer, what about a filtration syatem? Do I have to dose any calcium or alkalinity? Just how much water to do have to change weekly?

Unfortunately there is no decisive answers for these particular concerns because every aquarium is different. There are though general arguments to follow for every reef tank.

The most important factor in keeping any reef tank is water quality. You can have the coolest lights, the "best" additives, etc, if your H2O quality is not just right, you will not have a healthy reef. The easiest way to maintain optimal water quality is by performing water changes. Since nano's have such low water volume, one can perform 50% water changes once a week without even drawing a sweat!

All you would have to keep up your nano reef aquarium is salt and an RO-DI unit! Yes, you still need the obvious items such as lighting, temperature control, water motion, regular food, etc, but you will most likely not require any type of filtration. No protein skimmer, no carbon reactor, no phosphate reactor and no mechanical filtration as well. You will most likely not even need to worry about dosing for calcium, alkalinity nor magnesium!

But just how?

Simple, you will get EVERYTHING you require from a simple and easy water change! Remember, you have a 10 gallon tank. Even if you mix a 5 gallon bucket of fresh salt mix weekly, you will be changing out roughly 50% of your H2O. A 50% water change will most defiantly boost any calcium, alkalinity and magnesium and it will also get rid of all the "bad stuff" that a skimmer or sump would have gotten rid of!

The only issue I have with large 50%+ water changes is they could dramatically alter your water chemistry. This would be ok for a fish only aquarium, but if you have any type of coral, I would certainly not suggest it. What you can do is mix your 5 gallon bucket of fresh salt once per week BUT only change a couple of gallons at one time, say every couple of 48 hours. This way you still get the benefit of a 50% water change once a week without shocking your corals with any large changes.

Important note** Keep the mixed seawater covered to protect it from debris getting in and to minimize water evaporation. If water evaporates, your salt mix will generally be comprised. As you are probably already aware, salt does not evaporate, only water does. Make certain you check your salinity before dropping it in!