Live sand from the bag is like uncured rock , in the way that it contains dieoff, so this Alone is enough to start a cycle but nit enough to sustain a "bioload" or be a filter. Alot of people run barebottom tanks (no sand)
koralia nano is fine indeed but I don't like how it's one piece (mine is anyways) makes it hard to clean.
Refractometer over hydrometer , hydrometers are not accurate
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