Some people have expressed concern that the rapid reduction of nitrates would "shock" the tank critters. This is an understandable concern, but under the circumstances wouldn't you think that the rapid reduction of potentially harmful toxins in a tank to be of the utmost importance, and a lot less harmless? It would be like standing in a closed garage with a car engine running, filling the garage with carbon monoxide, and someone telling you not to open the garage door; that the rapid reduction in carbon monoxide levels would in some way be more harmful to you than only reducing their levels by 20%. If it was me in that situation, I would kick the door open as far as it would go.
To avoid the urgent need to have to reduce high toxic nitrate levels, it is much easier to following regular maintenance and water change routines. If you are in a position where everything you have tried does not seem to work and your nitrates continue to be a problem, you might try this water change method out.
We wanted to see what the results and effects would be of performing this water change process as quickly as possible. No problems resulted. However, if you are concerned about "shocking" your tank inhabitants, you can always perform this process over a period of time (waiting a few days between each water change process) until the nitrates are reduced.
