How many of you readers have ever wondered: "How do other
aquarists in other countries solve this problem ?" or "Am I
doing things right ?...... I wish I knew what fellow aquarists
would do in this situation !" ?.
During spring 1997 we wondered if it would be possible to log
the status of the reef aquarists on an international basis? It
would obviously be most interesting to compare statistically the
status of the hobby from different parts of the world. Are there,
for instance, major differences in the use of technique in German
reef tanks versus American reef tanks? Or, what are the biggest
difficulties encountered by European aquarists, and are these the
same as those which are troubling aquarists elsewhere in the
world? We had never seen any surveys previously done on this
subject, at least not extensive ones, nor on an international
basis. We had no doubt that it would be worth the effort to carry
out such a survey on our own; - so we decided to give the
international survey a chance !
The rapidly growing use of Internet world-wide gave us
the possibility to, in a simple way, spread a survey to many
countries, while - at the same time - aquarists could respond
without using stamps and envelopes. Furthermore, on order to get
reasonable coverage also in countries where the use of Internet is
less common, we distributed copies of the survey form per snail
mail to aquarists societies and shops for them to distribute among
their members/customers.
When reaching the end of August, the deadline for
participating in the survey, we had got a total of 683 answers
from 33 countries. See details below.
Statistic material can be treated in different ways. In all
surveys some answers tell you a lot while others are of little
value. When the survey is done and the results are counted, you
are bound to discover that some questions should have been phrased
in another way, or that you rather should have ask about other,
more or less related, topics. Still you have to do the best out of
the material you actually have, and in our case we believe we have
uncovered highly interesting trends and tendencies, indeed. In
order to cover the few aspects where we should have asked
differently to get clearer results, we'll have to get back to you
all on another occasion.
We used Microsoft Office-97 EXCEL spreadsheet for
treating the answers and estimating the relative frequencies of
each question. The number of answers is named "n", meaning
that if we look on all answers world-wide as one, single group,
where n is equal to 683. If we, however, look at answers
from Germany only, then n equals 155. See further details
below.
In many of the questions one and the same aquarist marks
several alternative answers. We have chosen what is normal
in such cases, to look at each single answer-alternative as a
separate question. Let us look at question #22 in section C as an
example. The question sounds:
For adding calcium I use:.....
......and has the following answer-alternatives:
ß no adding
ß "kalkwasser"
ß "kalkwasser" and CO2
ß "kalkwasser", CO2 and pH-control.
ß Carbon reactor with calcareous material and
CO2-adding.
ß Carbon reactor with calcareous material,
CO2 and pH-control
ß other type of calcium adding.
From Germany, where we got 155 forms back, question #22 gave
189 markings. Some aquarists use more than one way of adding
calcium and have, of course, checked more than one alternative
when they answered this question. Consequently, when we estimate
the relative frequency (in %), and look upon each alternative
answer in question 22 as a separate question, we get a sum higher
than 100%. Those aquarists that have checked more than one
alternative, count for two or more aquarists, depending on how
many alternatives they actually checked. Table 1 shows the result:
TABLE 1:
Alternatives
Number
% (n=155)
No adding
11
7,1
Kalkwasser
79
51
Kalkwasser + CO2
5
3,2
Kalkwasser + CO2 + pH
control
3
1,9
Kalkreactor + CO2
36
23,2
Kalkreactor + CO2 +
pH-control
33
21,3
Other type of adding
22
14,2
SUM
189
121,9
In this case there are 34 aquarists or 21,9% that have checked
for more than one alternative in question #22. We can call this
group "multiple-answers". Potentially there will also be a group
of responders who have not answered the question, either because
they cannot, or because they will not answer to that particular
problem. We call this group "refusers". With respect to the
example above the group of "refusers" in fact counts zero as all
the 155 responders had answered question #22, but so is not the
case for all questions.
The divergence in the sum of the relative frequency above or
below 100% indicates how many "multiple-answers" and "refusers"
there are. It will not be totally precise to compare the results
of questions where the number of "refusers" are high with the
results of questions that have a low number of "refusers".
It will, however, be correct to compare two or more questions
which all have low numbers of "refusers". In any case the
different alternatives in each question can be compared with one
another. For instance the frequency for question #22 from Germany
clearly tells us that about half of the aquarists use "Kalkwasser"
while only a very small number use "Kalkwasser" combined with
CO2. This finding can in turn be compared with the
results for the same question in other countries or regions.
Alternatively we could have used n = 189 for question #22 and
used different "n"-values for each question where "n" was equal to
the number of markings in each question. This, however, would make
it even more difficult to compare the results.The number of
respondent world wide is shown in table 2:
TABLE 2:
Countries
Number of responders
USA
297
CANADA
17
Rest America
9
GERMANY
155
AUSTRIA
43
BELGIUM
36
SWEDEN
21
HOLLAND
17
NORWAY
17
FRANCE
14
Rest Europe
22
AUSTRALIA
18
Rest World
17
Total
683
The results are grouped in 6 different files to download:
R6: GERMANY (n=155) vs. REST EUROPE
(n=170) vs. REST WORLD (n=358)
The results are official and you are welcome to use them for
your own purposes. We would be happy if your local aquarium club
would discuss the findings. If you use it in your club-magazine or
equal publications, we would, however, greatly appreciate
receiving two (2) copies of the publications for our files. Please
mail to: Alf Jacob Nilsen, P.O.Boks 142,
N-4401 Flekkefjord, Norway