removing 1/2 the fish = recycling tank??

[new2natives]

i am about to sell some of my fish... probably about 1/2 of them

the tank is a little overstocked at the moment, and so there is a medium-heavy bioload on the tank

if i take all of those fish out at the same time, will that cause a lack of bio for the filters, and cause the filters to recycle??

 

[BMueller777]

I'm going to say no only because it really wouldn't make sense for the tank to recycle after being able to handle X amount of fish and then having Y amount which is less.

Maybe the "extra" bacteria will die off and settle to the level of the new number of fish.

I've only heard of tanks recycling because of too much media replacement or a massive amount of added fish, not because they were taken away.

Just my opinion though.

If anyone else knows the legit answer to this question please let us know because I'm actually getting rid of some fish too, more then 1/2.

 

[snake_charmer]

No

 

[Stump]

BMueller777 is right. The bacteria that is not getting enough ammonia/nitrites to thrive will simply die off, leaving the bacteria that is getting enough to stay alive. There is no reason for it to cycle again, at all. The only thing you need to worry about is enough bacteria - which isn't a concern if your tank is already cycled.

 

[jcardona1]

youll only have a problem if you largely INCREASE your bioload all at once, not if you DECREASE it. youre ok

 

[tcarswell]

Ditto , If you plan to add more fish you could try feeding a little extra until you get the new fish. this will cause the remaining fish to excrete a little more ammonia for the bacteria to break down hence keeping a little extra bacteria alive til you get more fish. I couldn't recommend this method for more than a week.