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Too Tall for Cories?
I have a large hexagonal
aquarium (not sure exactly
how many gallons) that I
would like to stock with Corydoras catfish.
But my dealer told me the tank is too tall.
What do you suppose he meant by that?
Well, you’d probably have to
clarify that with your dealer.
Based on the wording of your
question, there’s more than one
way to take his comment. He could have
meant that he thinks the tank is too tall for
keeping fish in general, perhaps alluding to
the less-than-optimal surface-to-air ratio of
taller, narrower tanks, which provide poorer
gas exchange at the water surface than
shorter, wider tanks do. But that limitation
doesn’t preclude keeping fish in hexagonal
tanks. It just means you have to be careful
in how you stock them and take measures to
Another possibility is that he thinks the tank
is too tall specifically for keeping Corydoras
catfishes. Cory cats must regularly swim
to the surface to gulp air and, being bottom
dwellers, appreciate an aquarium with ample
bottom space. Hence, they generally do best
when kept in wider, shallower tanks rather
than taller, narrower ones.
I’ve noticed that nitrate and
phosphate are usually brought up together
in discussions about aquarium algae
control. I have a pretty decent grasp on
the nitrogen cycle, so I understand where
nitrate comes from, but how exactly does
phosphate get into aquariums and how can
you control it?
Phosphate arrives in aquariums
via many of the same sources that
fuel the nitrogen cycle, such as
decomposing fish waste, uneaten
food, deceased specimens, etc. It can also
be present in aquarium additives, activated
carbon, and even your tap water. Of course,
as with nitrate, phosphate acts as a wonderful
plant fertilizer, which is why these two terms
are so often mentioned together in relation to
The steps for minimizing phosphate in
your aquarium are essentially the same as
those for minimizing nitrate—i.e., frequent
partial water changes, conscientious tank
cleaning and maintenance, and avoiding
overstocking and overfeeding. If you’re
practicing good aquarium husbandry yet
still experience an elevated phosphate level,
then you should look to external sources
such as your tap water or any additives you
might be using.
First of all, I would like to
say how much I enjoy your
magazine. It is one of two
magazines I will read cover to cover. I
am having a problem with one of my
male double-tail bettas, Miharu. He has
been jumping over the divider into the
compartment of his tankmate Orchid,
a black and steel- blue half moon betta.
Miharu and Orchid share a 10-gallon
aquarium with one other betta, a super
delta tail named Kyrios. Surprisingly,
Orchid did not try to kill Miharu. I have
taken steps to try to keep Miharu in his
compartment. My other two double tails,
Setsuna and Ribbons, share a 5-gallon
aquarium and do not show this behavior.
Why is Miharu doing this? He has done
it twice. Also, the five of them will hide
in their plants if a stranger looks at
them. Why would they do that?
Amanda R. Sanocki
Woonsocket, Rhode Island