How Many Fish Should I Put in My New Tank?

You will hear a lot of recommendations for thethe most deadly combination there is in the
amount of fish to add to a newly establishedbeginning aquarium.
aquarium. The heartbreak is that most people willAfter a month to six weeks, the fish that have
ignore the limits and add "just a few more,it can`tbeen in the aquarium have experienced the rise
hurt, right?" Wrong!! A few weeks later, thatand then sudden drop of nitrogenous toxins,
extra bioload has produced enough toxic ammoniaammonia, but especially nitrite and the biological
and nitrite to crash the whole system.filter has been properly established. It is a time of
The cardinal rule for any novice aquarist should beanticipation for the aquarist as new fish can finally
patience. The less fish added in the beginning andbe added to the habitat.
allowed to help the biological filter mature, theAt this point the second half of the rule becomes
better.relevant. I suggest that the maximum amount of
With this in mind, the best answer to "How Manyfish the aquarium can safely accommodate is two
Fish in a tank?" is a two part one. The first half isinches per gallon - but this is actually greater than
the rule for adding fish to a new aquarium, anddouble! In this calculation I suggest it is possible to
the second half is used when the Nitrogen Cyclediscount the tails, and measure only the actual
has been firmly established and new fish can bebodies. This does greatly increase the the capacity
finally added to the system.for supporting fish to a much higher level.
One inch per gallon (3.78 L) is the established ruleI would caution here, that suddenly doubling the
for a brand new aquarium. People pretty muchbioload will cause serious problems for the biofilter.
agree on this, but the issue gets clouded whenThe bacteria do have a lag time to react to
the further question is asked: "Just the bodysudden changes. The best method is to apply the
length or with the fins included?" In this case, Irule to the community, but only gradually work to
prefer to use the entire length of the the fish,the upper limit. Add only a few fish at any given
with the finnage included. Most starter fish do nottime. If the species is a schooling fish, add just
have long flowing fins, with the possible exceptionthe correct number of fish for a good school and
of the Betta, so this is really not a hardship, andthat would be it. Wait at least a few days before
the stricter definition ensures the load on theadding any more to allow the bacteria population
system will be relatively light - just what isto adjust to the increased ammonia load the new
needed to produce a strong and vibrant bacterialfish will provide.
mix, but help prevent extensive overfeedingTake your time with building up the population,
because of the scarcity of fish.everyone will be much happier for it.
The combination of fish load and excess food is