Saltwater Fish
Marine Invertebrates
Acclimation
Feeding
Saltwater Aquarium Conditioning
(The Nitrogen Cycle)
In some of the previous sections I've mentioned the conditioning process. Now it's time to get into some detail on this very important subject. You may also recall from previous sections that I talked about biological filtration and the bacteria that will colonize your gravel bed. These bacteria play an absolutely critical role in converting some of the highly toxic elements in your tank into fairly benign chemicals. In fact, this process is so critical that your animals cannot survive without it. You don't need to be a chemist to understand the process, but you do need to have a fairly solid basic understanding to give you're new aquarium a fighting chance. So let's have a quick review:
Animal waste products, leftover food and other organic materials in the aquarium decompose producing ammonia. This is extremely toxic to the animals in your tank and will quickly kill them if the level of ammonia in the tank rises too high.
One type of bacteria in the gravel bed converts the ammonia to another chemical called nitrite. Nitrite is also toxic, although less so than ammonia, but will also lead to the demise of your animals if not removed.
A second type of bacteria in the gravel bed then converts the nitrite to another chemical, nitrate. Nitrate, although not immediately toxic to most
saltwater fish, is not well tolerated by
many of the more delicate sea creatures such as corals and invertebrates. Nitrate will gradually accumulate in your tank and can only be effectively removed by regular water changes.
Nitrate will also act as fertilizer for plants and algae,
but they will not consume sufficient amounts in the aquarium
to keep the nitrate level in check.
The bacteria that perform this process are not in the gravel that you bring home from the pet shop or in the saltwater mixture that you use when you setup your tank. It will take time for these bacteria to grow naturally and colonize within your gravel bed. This process is known as conditioning or cycling, and here's the basic process:
You add new (hardy) fish to your new setup. Over the next few days they will consume the food that you feed them and produce natural waste products which will break down naturally and produce ammonia as a by-product. During the first two weeks the ammonia level will rise and peak after about 12 - 14 days. Fish that are particularly delicate will not be able to tolerate the ammonia in the tank and will likely die, so make sure you use strong, hardy fish for this stage of conditioning. Damselfish are an excellent choice. The ammonia in the aquarium will trigger the growth of the
nitrifying bacteria known as Nitrosomonas bacteria.
This nitrifying bacteria actually feeds on the ammonia and converts it to a somewhat less toxic chemical, nitrite. As the nitrifying bacteria spread and colonize your substrate they continue consuming ammonia and releasing nitrites. During this part of the cycle, ammonia levels will begin to decrease and nitrites will steadily increase. These nitrites are also toxic and need to be removed. Luckily, a second type of
denitrifying bacteria, known as Nitrobacter bacteria, will feed on the nitrites and convert them to nitrates. The nitrite level in your aquarium will peak about 6 - 8 days after the ammonia level peaks, putting you into week three of the conditioning process.
The denitrifying bacteria continue to grow and colonize the substrate and feed on the toxic nitrites, converting them into fairly benign nitrates. At this point the nitrite levels should steadily decline and the nitrate level will slowly rise. Most aquarium fish are not particularly sensitive to nitrates, although many invertebrates and corals will not tolerate even moderate nitrate levels. The only way to effectively remove these nitrates is with regular water changes.
Once this cycle is complete the ammonia and nitrite levels should settle below 0.1 ppm (parts per million) and should now be safe for most marine life.
Simple test kits are available at your local pet shop that can measure the levels of ammonia, nitrite and nitrate in your water. Most of those same pet shops will also test a sample of your aquarium water for a small fee. Either way, check the levels at least once a week during the conditioning process and track the changes. This is the only way to be sure that your tank has properly cycled.
The entire conditioning process can take close to one month to complete. This is where most new aquarists make their biggest mistake. After spending a decent amount of money on their new system and investing the time to construct it, they grow impatient and want to populate the tank with other types of fish immediately. Remember, if the fish that you add to the tank cannot tolerate the peaking levels of ammonia and nitrites, they will die. Sometimes they will be dead the next morning, and sometimes they may survive for a month or more, but the damage has been done and they will ultimately succumb to the toxic affects that the ammonia and nitrites have done to their internal organs and gills. Do yourself a favor and have the patience to do it right.
All of that being said, many aquarists (including myself) use a simple trick to speed up the conditioning process. If you know someone who has an established, healthy aquarium, (the key here being healthy) you can take a scoop of their substrate material and add it to your new substrate. The gravel taken from the established tank will be teaming with these bacteria and they will grow rapidly and spread into your own substrate. I will emphasize again; make sure the tank you are taking this gravel from is healthy. Home aquariums are small, enclosed eco-systems and anything, good or bad, that you take from their tank will end up in your tank. Keeping this in mind, I highly recommend that you do NOT take established gravel from a pet store to help speed up your conditioning process.
Some may argue with me on this point, but you never know what animals, healthy or otherwise, have been in their tanks. Whatever those animals had will likely be in the substrate and will then be transferred to your new "pristine" aquarium. Definitely not worth the risk.
When you're done here, check out
some of these other aquarium sites:
Katy's Tropical Fish
Angelfish Revealed
SaltWater Aquarium Advice
Tropical Fish Secrets
Aquatic Experts
Starting A Reef Tank
