Reverse Cycle

[melissa903]

I read an article posted here about reverse cycling a tank using sodium nitrite. I would like to know where to buy sodium nitrite, how much to use, and are any other products (stability, etc) used as well.

[Tech Support DD]

Yes; you can reverse cycle a tank using sodium nitrite in order to establish the Nitrobacter population first. You may have to purchase sodium nitrite from a chemical company, which may not be the easiest task. However, keep in mind that you can cycle a tank using Stability with or without fish (without having to add any other chemicals).

[Jimbo205]

If cycling a tank means to start the biological filter; doesn't that infer that to 'Reverse Cycle' a tank would mean to STOP the biological filter?

I am visioning someone wanting to disinfect their tank ie: bleach.

Please explain the definition and concept.

Thanks.

[Tech Support DD]

I understand your reasoning :-) One can establish the biological filter in a reverse mode by the addition of sodium nitrite to establish the Nitrobacter population first and then the addition of ammonia to establish the Nitrosomonas. The bacteria are not fussy about their source of ammonia or nitrite, so that it is really not necessary to jeopardize a fish to establish the cycle. The main advantage of this reverse cycling (not to be confused with reverse flow) is the avoidance of the Nitrobacter inhibition by excess ammonia that ordinarily takes place in establishing a cycle. This ammonia inhibition of Nitrobacter is the main cause of cycle delays and failures.