I am new to the mailing group and to the internet. If I stuff up with
the etiquette please let me know, it is not intentional.
You will all discover soon that I can't spell, can't type (I regularly
hit the key next to the one that I want or get the order backawrd or use
the wrong word) and just plain leave words out. No point in telling me
about these errors, I have been like it for years and can't imagine that
I will suddenly get over it.
About the fish? I have been keeping them for about 25 years. Breed a few
in the early to mid 80's, mostly cichlids and Bristle Nose cats and
mostly by good luck rather than a careful plan. Got busy with other
stuff and got rid of some tanks and neglected the one that I still had
fish in it. I have been getting back into the hobby over the last year
or so and have been moving into rainbowfish. I no longer have any
cichlids.
Someone once wrote about me 'With Tim things fit into two categories,
things that need fixing and things that will need fixing once he has
found out why they work." Of cause they were wrong. Read on and see what
you think.
Why change the water? Yes, I know, if you don't the fish die, the plants
look like sh#t, etc. How do I know when I am changing the right amount?
Yes, I know, look at the fish and you will know. I have no doubt that
these answers are correct but my curiosity will not let it rest at that.
What started me on this study was this. During my recent period of
neglect I had a four foot tank, lightly stocked, heavily planted and
lightly feed (yes I forgot to do that to more often than I will admit,
when I'm getting four hours sleep a night self comes first). Over a two
year period I changed the water very few times. At times my guess is
that it went for more than six months without a change. Over the two
years I lost no more than five percent of the fish.
Next I started redecorating the house which involved moving the tank. In
the past I have noted that if water changes have been to few a sudden
large change will kill the already stressed fish. With this in mind
backed up by my natural instinct to measure everything. I went and
bought a Nitrate test kit. Because of everything that I have read about
the Nitrogen cycle, (end product Nitrate) I expected the reading to be
through the roof. The Nitrate level was undetectable, pH was 6.8. Now
confused but not distracted from what I believe I know I did ten percent
water changes every second day for three weeks before moving the tank.
When I moved the tank I reused 30% of the original water. All of the
fish survived.
Now curious I decided to do a few experiments. With the tank now stocked
and feed at more normal levels I maintained a reduced water change
routine, ten percent a month. I expected the Nitrate level to rise.
Still undetectable. I bought a new kit (what a waste of money!!) same
result. I am unwilling to continue with reduced water changes to prove
that the fish will die well before the Nitrate level rises to even
10ppm. If you accept that this will be the end result then the reason
for water changes is not to reduce the Nitrate level. Then why?
My attention has now turned to phosphate. Yes, the phosphate level
definitely rises in my tanks. I have resumed normal water changes (30% /
month). The phosphate level is about 10ppm. The level in Canberra's (I
live in Canberra) water supply is about 0.4ppm.
At this point I would like to make three points. I am NOT recommending
that anyone change their water change routine. I am NOT suggesting that
it is necessary measure any of these quantities. I AM interested in
hearing from those who have done their own experiments in these areas.
I have the following questions
- What effect does phosphate have on the fish?
- What level is OK for the fish / plants?
- What other substances (of interest) accumulate in a fish tank?
- How do people living in places like Adelaide get on? Is the nutrient
level in the water supply high?
My interest is in things that can be measured and proven rather than the
abstract even though the later may in the end be all we really have to
make our decisions by.
To those who have managed to read this far, thank you.
See Ya
Tim T.