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pH Value for Killis
Hello Wright, Thanks for your very comprehensive message about water
chemistry (and stores). I agree completely on most of your statements except
that I consider the pH as an important parameter. I did not always think so,
but I have changed my point of view regarding the pH since I measure it
regularly with a (calibrated) pH meter. When I started to measure first the
pH, I must admit that I was rather surprised about the results. The values
in my tanks ranged in-between 7.5 and 8.9, depending on the hardness of the
water (tab or RO/tab mixed), how heavily they were planted, and if there was
peat in the tank. The tendency was completely in agreement with my
expectations (tab water, lots of plants and no peat results in high pH) but
the absolute values I would have expected lower! The fish did actually well
in this water (I keep mainly small Aphyosemions) except for two points:
There was never fry coming up in the parents tanks and some species did not
spawn although the females were full of eggs. Then I started to adjust the
pH to lower values, e.g. between 6 and 6.5 for breeding pairs and aprox.
neutral for fry and young fish. The change was striking! Most couples (that
did not spawn before) started to give lots of eggs and for me even more
important, within some weeks after lowering the pH value, in most of the
tanks fry started to show up together with the parents. Of course it would
be too easy just to say now low pH = eggs and fry... In the case of the
couples that did not spawn (even so the female was full of eggs, not an
uncommon problem I think) the pH CHANGE and not the ABSOLUTE pH may have
triggered the spawning. Maybe it's unimportant if you go from 7.5 to 6.5 or
from 8.5 to 7.5 or even from 6.5 to 7.5... I wouldn't be surprised. It is
also a fact that eggs CAN 'survive' a higher pH. For example I collected
eggs from joergenscheeli at a pH of 8.2 and stored them on peat and hatch
them in RO/tab mixed at pH 7.5... no problem. But in the tank were the pH
used to be in-between 7.5 and 8.5 I never saw one fry. (It changed
'immediately' when I lowered the pH to 6.5.) Maybe the lower pH is just
leading to a better 'microclimate' in the aquarium where it is harder for
bacteria and fungus to survive (and therefore easier for the eggs?!). Again
I don't know. For me it is just clear that I monitor and watch the pH
carefully now and in the future.
This leads me actually to the next question, how to lower the pH. The tab
water I have has pH 8 and I was considering several acids to put the pH
down. Like Wright has pointed out correctly, there is of course the danger
of creating a chemical soup... we need 'the acid' (H+) but together with it
we get the counter-ion with it's unpleasant properties... Organic acids
stress the system because they have to be degradeted so I don't like them.
Nitric acid is out of discussion because of the nitrate anion. Hydrochloric
acid or sulfuric acid have counter-ions that I would consider as 'rather
harmless', but they are strong acids and therefore not ideal to create I
stable system. Phosphoric acid is a sufficiently weak acid but the phosphate
may lead to algae explosion. Well finally I have decided to use phosphoric
acid (and I think that's also the main ingredient in most of the commercial
products - just 500 times more expensive...) and so far I'm satisfied. In
aquariums with no or little plants (and light) one gets indeed a very fast
algae growth, but in my well planted aquariums I observed an excellent
plant growth and no algae! Once the pH is adjusted, it stays quite stable.
The difficult thing is to adjust the pH. It depends of course enormously on
the buffer capacity of the water how much acid is needed, for example I need
about 1 ml for 10l of tab water but only two drops for the same amount of RO
water. Even so I have now more or less the 'experience' how much it needs, I
would never dare to work with the acid without control of the pH value.
As a conclusion I would say: If you have no problems with your fish and they
breed willingly, forget about the pH, your water must be good, why should
you change anything!!! If you have no intentions of breeding the fish, again
the pH is much less important than having CLEAN water. But if you have
problems, consider to have a look at your pH. To give it a first try,
commercial products are OK, and affordable as long as you want to try it in
one or two small breeding tanks. Negative side effects like algae growth can
show up, but since most killi breeders are quite tolerate to the 'aesthetic
appearance' of there (breeding)tanks (or do you think mops look very natural
in a rivuline biotope...) I consider it as a minor problem.
And a final last WARNING: Like it has be pointed out before by others in
detail: The handling of acids and chemicals in general may be dangerous to
your health!!! Handle acids only with the appropriate care and always
'know' what you do before you start to pour any stuff in your aquariums - if
not the disaster is predictable...
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