Nitrifying bacteria blooms in of themselves are not harmful and will self consume/ find a home over a couple days. In other words you don't have to do anything.
However, not knowing your system volume or what "double" is, it's hard to say whether you would have an ammonia then nitrite peak of potentially toxic levels. Unless you dumped a 1/4 cup of mysis in a just cycled 20 gallon, I suspect you will be fine. If you have concerns, test for ammonia and watch your inhabitants for signs of stress. If you have high ammonia values/stressed occupants/just can't sleep, do a couple back to back water changes.