[leebca]

After reviewing the List of Posts (Table/Contents - Link List) I realize there is still somethings that need to be made clear to the relatively new hobbyist. This post is about the microbes in the marine system that are not part of the nitrogen cycle. They perform the 'secret cycle.'

One thing the new aquarist usually doesn’t understand is why they can’t add fish to an aquarium just set up with live rock and live sand. The perception is that the nitrifying bacteria are there and going to work right from the beginning, so marine life should be able to go right into the aquarium. In this situation, the aquarium doesn’t seem to cycle, or does it?

Many LFSs try to tell their customers to go ahead and start adding lifeforms to the aquarium, including fishes. This is not good advice -- unless you want to sell a lot of fishes. The aquarium still must cycle, even if it isn't the nitrification cycle.

In the ‘old days’ when we sat around waiting for the aquarium to show a dramatic drop in ammonia and nitrites, the clock ticked on. Weeks or months passed while we waited for the aquarium to cycle. Even though we measured ammonia and nitrites there were other things going on in the aquarium. Millions of dozens of other microbes were setting up housekeeping. Those that feed off of organic matter and produce other wastes; bacteria that feed off the wastes of other bacteria, even microbes that feed off of bacteria were gaining in numbers and finding niches. Their numbers would wax and wane like the tides until, after the additions of nutrients (fish food, fish waste, rotting things, detritus) reach a more or less stable state, their own populations would reach a stable state. This was in part taken into account while the aquarist waited for the nitrifying bacteria to settle in and convert ammonia to nitrite and nitrites to nitrates – until the tank cycled. During this time period, there was another cycle going on -- the secret cycle of these other microbes.

But now, the nitrifying bacteria are there from the beginning and in usually large enough numbers to handle ammonia and nitrites. They come with the rock and live sands. That waiting for weeks and months to cycle the aquarium doesn’t seem necessary. But it still is.

There must be time for the other bacteria to settle in and get used to the nutrients being added to this confined area, our marine system. Plastics, glass, glues, propellers, etc. all have to age. Not only for the microbes, but for the higher lifeforms.

The live rock has brought with it (hopefully) many small animals and plants that form a microbial and higher lifeform layer in the marine system. They have to grow, and find their own niche. Some eat the bacteria that are trying to multiply and establish themselves. Some microbes prefer to live in polluted water so they will show up early (e.g., brown ‘algae’) and leave when the tank has matured. Others will feed off of light and other nutrients.

In order to get this ‘secret cycle’ going, the aquarist sets up the aquarium with the live rock and lets things settle. Then after some time when the live rock life seems to spring out of hiding, the aquarist introduces clean up crew and slowly introduces higher lifeforms. All this time, the aquarist begins to feed this life and thus begins the introduction of nutrients into the aquarium system. The microbial and lower life forms react to the introduction of these nutrients and wax and wane in numbers as their food/nutrient availability, competitors, and predators will allow.

This is why there still needs to be time to age a FOWLR aquarium. There is a secret cycle that has to take place and can’t be rushed by any aquarist. It is controlled by Mother Nature, and She takes her own time.

So as you read the recommendations for starting up a FOWLR aquarium given here: Setting Up a FOWLR Aquarium remember what isn’t being tested for and just has to be waited for -- this secret cycle of the microbes we don't test for.