Letters to the Editor
In the question “Anemone Mystery” from “Q&A
Saltwater” of the January 2008 issue, the writer,
who is experiencing difficulties with his specimens,
says “...but my light intensity hasn’t changed. (I use
This may, in fact, be his problem. My experience,
and that of some other good hobbyists I know, is that
compact fluorescent lamps have very bad degradation
curves—they lose a lot of their light output within
the first year. I used to be in the energy-efficient-lighting business, and I talked to some guys I used to
work with who are still in the biz, and they concur.
Manufacturers don’t seem to publish any degradation
curves for CFs as they do for other linear lamps,
which show that T8s lose about 10 percent in the
first 1000 hours, and then do not degrade beyond
that until their useful life of 14,000 hours. T5s are
even better. Many people advise hobbyists to replace
the lamps every year. I wish I could have all of the
T5 lamps that hobbyists toss out at the end of a year,
since they still have around two more years of good
light output in them.
I really think that this guy’s problem is that the
light from the CFs decreased dramatically, and
stressed the animal.
Thanks for your email. Very few of us have access
to physics labs where we could test the advice we get.
Reef or planted tank aquarists who rely on compact
fluorescent lighting should find your input useful!
My wife and I have decided to get back into this awesome
hobby (after a 15-year hiatus), and we’re committed to
starting a cichlid tank. Our question concerns water
quality. We rely on collected rainwater stored in our
16,000-gallon cistern (thus softer than typical city water).
What are the issues we need to be aware of as we begin our
new tank? We’ve been told by our local “experts” that the
greater Cincinnati area has water hardness levels that are
great for cichlids, but when I tell them our water supply is
rainwater, they give us a confused look that concerns me.
We want to start by doing things the right way. Please help.
Dawn & Steve Heinen
Welcome back! There is no such thing as one hardness
level that is “great for cichlids,” since cichlids are
found in every type of natural tropical aquatic habitat,
from extremely acid with no measurable hardness to
extremely basic with hardness so high that calcium
and magnesium salts precipitate out, from rainwater
pure through brackish to full marine. If you wish to
keep cichlids from the African Rift Lakes or from
Central America, you can purchase special Rift Lake
salt mixes to add to your rainwater; while if you want
to keep blackwater Amazonian species, rainwater is
ideal—although you should consider adding a buffer to
counteract normal pH drop, which in an aquarium can
be rapid and drastic in water with no alkalinity. There
are, however, several issues about using your cistern
supply that you should investigate, not only for your
fish’s health, but for yours.
First, old rain collection systems were engineered
before a lot of health issues were considered, and newer
ones were often intended for washing, firefighting, and
uses other than drinking. Then, most cisterns collect
off roofs. Many roofing materials can contaminate the
water with undesirable chemicals, a problem made worse
in areas with acid rain, since the low pH can dissolve
even more substances, and in urban areas the rain is
often far from pure. Today a lot of shingles incorporate
elemental copper for the purpose of retarding the
growth of algae and fungi, but water flowing over them
may pick up a toxic level of copper. Also, being open,
rainwater recovery systems are always vulnerable to
contamination from wildlife and natural debris—a
dead sparrow under a pile of rotting leaves on the roof
can spell disaster.
If your water system is certified safe as potable
water, it should be safe for your fish, but only for
fish adapted to extremely soft, acid water—which
includes a great many cichlid species—provided you
make extremely frequent water changes and/or use
a buffer against pH drop. For the majority of cichlid
species, you will need to add minerals to the water
or mix it with water from another source, such as a
well or municipal water supply.
In any case, good luck with your new tanks! D
EMAIL By far the best way to communicate with us at TFH is by email. To ensure that we receive your message, avoid the use of account
names and subject lines that are likely to trigger junk filters. Probably the best subject is “Q&A.” Due to the volume of mail, we are unable
to respond personally to all, but every message is read.
If you are writing for some purpose other than submitting a question (submitting an article, for example), feel free to tap on the glass and
send another message if you do not hear back in a reasonable amount of time. Attachments that are not accompanied by an explanatory
message or query are deleted unopened.