HOW TO QUICKLY REDUCE NITRATE LEVELS IN A SALTWATER AQUARIUM
Nitrate is the end product of bacteria reducing ammonia to nitrite and then to nitrate. Nitrates will accumulate in the aquarium water until they are assimilated by the plants or removed by water changes.
In fresh water, nitrates are relatively non-toxic even at high levels (200 mg/l or more), but in marine aquariums this can be a problem for marine invertebrates, so they should be kept at lower levels (below 20 mg/l). Some marine aquarium owners are reluctant to carry out regular water changes to reduce nitrate levels as they would then need to add more salt to the water, with the result that they only top up with fresh water to replace the evaporated water (as the salt does not evaporate). All this does not remove the nitrates, but even increases their content in the water.
The proposed method of nitrate reduction is an instant water change to reduce nitrate levels. You can quickly reduce the nitrate content to zero without any painful or harmful effects on the aquarium inhabitants. You will notice that the fish become more active, begin to eat better and show a brighter coloration after a few days.
Important clarifications
One important clarification before starting a full or partial water change is to remember that the pH of the water will also change in the process (possibly upwards). Before proceeding with the water change, it is advisable to slowly adjust the pH of the water in the aquarium to what it will be after it is completed. You can raise the pH with ordinary baking soda or lower it with one of the many products on the market to lower the pH of the aquarium water. This will prevent a so-called "pH shock", which can be fatal for the more sensitive aquarium inhabitants.
Quick nitrate reduction method
Many people try to reduce nitrate levels by performing a series of partial 20% water changes. Of course this will reduce nitrate levels (or any other chemical), but this is rather ineffective if the goal is to reduce levels to almost zero in the shortest possible time and with the minimum amount of water.
For example, if you reduce the water level in the tank to 20% of normal and then fill the tank again to 40%, you have already reduced the nitrate level by half. If you then fill the tank to 100%, your nitrate level will be 20% of the original level from which you started.
On the other hand, if you reduce the water level from 40% again to 20% and then fill the tank again, you will get a nitrate level of 10% of where you started from. So, if you started with a nitrate level of 100 parts per million and used this method, your 100 parts per million nitrates will be reduced in a short period of time to five parts per million, which is considered an acceptable level even for corals.
Why it's safe
Some fear that the rapid reduction of nitrate levels will "shock" the aquarium inhabitants. Such worries are understandable, but under the circumstances, a rapid reduction of potentially harmful toxins in the aquarium is of paramount importance.
Of course, the best way to avoid acute need to reduce toxic nitrate levels is to carry out regular maintenance work and aquarium water changes. If maintenance of the aquarium fails to lower the nitrate level, try the above method of water changes.
