Marine Setup Step 8 - Inoculate Your System
From Microcosm Aquarium Explorer
[edit] Seeding the Good Bacteria
By Robert M. Fenner from The Conscientious Marine Aquarist
At this point, we are ready to add the first livestock—the microscopic and all-essential bacterial cultures—to the aquarium. These do the all-important tasks of breaking down toxic nitrogen waste which can kill livestock if not "cycled" into non-toxic forms. (See Marine Nitrogen Cycle.)
Be sure your tank water is hospitable: right temperature, specific gravity, and pH. Never add anything alive to freshly mixed seawater, including bacterial cultures.
[edit] Tip
My recommendation is to start with a cup or two (a pound or so) of gravel or live sand from a healthy, long-established marine aquarium. This will be filled with the beneficial microbes needed to “seed” your system.
Other sources are filter media from another marine system, including activated charcoal that has been in place for a couple of months, biomedia, live rock, or any other material that has been colonized by the needed bacteria. (Commercially packaged cultures are available, but many aquarists have had consistently better luck launching their systems with fresh.) A quart of water from a healthy, long-established marine aquarium will also help inoculate a new tank.
You also need to add a source of nutrients to feed the bacteria and encourage them to proliferate. Aquarium shops can sell you ammonia, which will serve the purpose (follow directions explicitly and do not overdose).
A livelier alternative, and the traditional approach, is to add a few rugged appropriate damsels or blennies that can survive the initial cycling of the system.
Their waste products produce the essential ammonia. Other choices are bait shrimp or bait fishes, if these are available locally.
Some aquarists simply add fish food or scraps of raw fish; as they decompose, the desirable ammonia is released.
The problem with adding damsels is that you may be stuck with bullying characters once the tank is ready to be stocked with more desirable species.
Monitor and record the nitrogen cycle until there is no measurable level of either ammonia or nitrite. This generally will take from 4 to 8 weeks, at the most; with live rock and/or live sand, the cycling process should occur much more quickly. (If good, cured live rock and live sand are used, cycling may happen almost overnight.)
During this period, you will likely see growths of brown or golden diatoms and the beginnings of green algal coverage. Feel free to keep up appearances by brushing these off the front and side viewing panels.
If algae seem to be overtaking your decor, you may want to add a living maintenance crew in the form of snails (Lithopoma [Astraea] species; Turbo species; or others) and small herbivorous hermit crabs.
Reef aquarists stock as heavily as one snail or hermit crab per gallon of tank capacity. These will not keep glass surfaces perfectly clean, but will do a good job on rockwork, substrate surfaces, and in other nooks and crannies of the aquascape.