I have a 90-gallon freshwater
tank with all live plants and
an assortment of fishes and
recently noticed what I would
consider an outbreak of ramshorn snails.
They are very small and most likely hitched
in on the last bunch of plants. I’m concerned
about their getting out of control. Could
that the wat
There are two problems with
plants and undergravel filters.
One is that you need a fairly
large gravel size to make sure
er can pass through the substrate
evenly, but plants prefer fine gravel or sand.
The other problem is that since the gravel is
the filter medium, it can become clogged with
debris, and the bacteria associated with it can
rot the plant’s roots.
To circumvent both problems, people who
want to grow plants simply utilize pots for
the individual plants. This is a solution that
I have seen used successfully many times. In
fact, I’ve seen plants growing without pots in
tanks with undergravel filters, and they were
doing well. But my understanding is that
these are exceptions to the rule.
I’ve always kept fish with
filters, but I haven’t kept plants
before. I’m told that it is pretty much impossible
with undergravel filters. Is that true?
that piranhas are not dangerous to people.
And the natives in South America know it,
too, as the presence of piranhas in the water
doesn’t keep them out of it.
The true power of the piranha is the impact
of a school. Piranhas work as a group, and
they need others to do their dirty work
properly. But they still do not usually attack
unless a fish or other animal shows signs of
distress or of being wounded. (The natives
probably would not go into the water with a
Keeping a group of piranhas can be a
little tricky due to their aggression and their
razor-sharp teeth, and it is best to put a group
in a large tank as juveniles. Once they are
acclimated to the tank and one another, they
will be a much more impressive display than a
single piranha. Just make sure that you don’t
let the cat fall in the tank!
Robust barbs like the cherry barb Puntius titteya should be able to hold their own with an
established school of tiger barbs.
Pygocentrus cariba; piranhas make a better display in groups than as single specimens in the
aquarium, but such an aggressive and toothy school would have to be properly introduced into a
suitably large tank and closely watched for excessive aggression within the school.
There are different species
of ramshorn snails, but the
ones you have are probably
Planorbis corneus, as that is
that be a problem, and if so how do I
control them without hurting my shrimp or
completely tearing my tank down?
the most common species in the aquarium
trade. You’re right, they probably did come
in with your plants. They certainly could
get out of control in the sense that your tank
would be crowded with these snails. There are
concoctions that will help kill off the snails,
but we don’t recommend such drastic action,
and in any case they could easily wipe out
your shrimp, too. A better control would be
some fish that eat the snails. Most cichlid