Ammonia Question

[mrcobrajet]

How do pet stores that sell fish control ammonia in thier tanks? They have alot of tanks and one day there is like 25 fish in 1 tank and the next day there is like 10 fish in the same tank and the day after that there is like 4. The ammonia levels would be spiking all over the place.
THANX

 

[fluttermoth]

Most LFS run banks of tanks off sump systems. There won't be one filter for each tank. Anyway, it takes a good few days to lose a whole colony of bacteria, and very little time for the colony to expand once a load of fish are added.

 

[N0body Of The Goat]

I know my local Aquajardin has a massive sump sectioned off from the public, that goes behind their square shaped doughnut sales tanks, it must be something like 20x1x0.5 metres!

Besides the shear scale of the sump, it was shocking to see how many fish were living in it that were escapees from the display tanks, apparently there was a 50+cm catfish living in there amongst tiny <2cm fish.