I returning to fish-keeping after a break of 3 years, but before that had
several aquaria and tried various filter methods over the years. I used to
get totally fed up with trailing cables, heaters coming un-suckered,
wobbling and detaching uplift tubes, pipes to and from external canisters
etc so I decided to get an all-in-one tank with all the machinery in a box
in the corner. The local aquarium shopkeeper's reply when I asked about
these systems was that he would of course sell me anything I wanted, but
what I really wanted was his cobbled-together package of bits as nothing but
undergravel filtration actually works, and no other method is able to
convert nitrite to nitrate. When I pointed out to him that I kept a tank
going for 3 years without losing a single fish and with plants growing out
of the top, with external filtration, he replied that my fish had been
living "on the edge" (but I didn't think cardinal tetras could survive "on
the edge"), and that "you'll only get nitrites converted to nitrates with an
undergravel filter". My last tank hardly ever had any detectable nitrites
and was obviously making nitrate somewhere, but he practically called me a
liar when I told him this.

Are there many like this one? Rudeness is not the way to persuade customers
to spend their hard-earned cash (rather a lot of cash, as it happened,
although he wasn't to know that as he never saw a penny of it), particularly
when another aquarium shop has opened 200 yards away, run by a very helpful
man and trading very well.

Duncan