Saltwater Reef Starter Kit

Tap water contains the phosphate, silicate, and trace metals that fuel nuisance algae and kill corals. Reverse-osmosis/deionized water is pure H2O — the only safe base for a reef. You mix it with a measured amount of synthetic reef salt. Tap water in a reef is a guaranteed algae farm.

Establishing the bacteria that convert toxic fish waste (ammonia) into less-toxic nitrate — a process that takes 4 to 8 weeks in a new tank, before any fish or coral go in. Add an ammonia source, test the water, wait. A tank that is not cycled kills everything you put in it.

It injects fine bubbles that attract dissolved organic waste (fish slime, uneaten food) and foam it out of the tank into a cup — removing waste before it breaks down into nutrients that feed algae. It is the defining filter of a reef and the main thing keeping the water clean.

Glacially. Cycle the tank (weeks), then add a cleanup crew (snails, crabs), then easy corals, then — after months — a fish or two. Every addition raises the bioload; the bacteria must catch up. The reefkeepers who crash their tanks added too much, too fast. Patience is the main nutrient.