Bron: koinations
The effects of pH and kH
As proved in the last issue of KOI Nations, mud pond water
isn’t just soft, it’s incredibly soft! To run such water hardness
levels in a filtered pond is virtually impossible, and this
is primarily because of pond and filter loadings. The
biological loading can actually be used to our advantage to
some degree. I’m sure that some readers will have noticed
that if your pond receives little food, the pH tends to run
at slightly elevated levels. This is because of lower levels of
acid by-products that are created due to the lighter feeding.
Heavy feeding produces more acid by-products, and hence,
a lower pH. We can play on this a little if we try not to load
a pond too lightly.
KH levels have a sliding scale effect on pH levels. Ultimately,
if a pond has an infinitely high KH level, this will
naturally (assuming no algal blooms) run at a ph of 8.4. A
low KH level will allow the pH to run at much lower levels.
Typically, a reasonably well-stocked and fed pond with a
KH of 2 ~ 3dH will run at a pH of somewhere between 7.2
and 7.5. But, if you removed the Koi from the pond, the pH
would rise from this level, and on a sunny day can rise very
high, very easily. If you maintain a healthy stocking level,
and feed the Koi well, you will find that a pond with lower
KH levels of say 2 ~ 3dH will have less of a pH swing, and
this is because the acids being produced by the Koi and
filters are being produced prolifically enough to keep the
pH from rising. Imagine it as say 100 KH ions being present
in 1 cubic meter of water. If the acid ions are plentiful, these
100 ions will become exhausted at a given rate. But, if the
same volume of water contained 1000 KH ions, then that’s
10 times as many ions, and as such can neutralise acid ions
a lot quicker. So, running a lower KH will enable you to
run a lower pH, but if doing so, you need to make certain
that this lower KH level is maintained very consistently
from day to day. If you don’t maintain the levels, they will
become slowly depleted, until the point that a pH crash
occurs.
If you are careful, and manipulate your KH levels inorder to be able to run a pH of somewhere between 7.2
and 7.5, the results will prove very rewarding. Please note
though, that although a well-loaded pond can help you run
more stable pH levels, if you overstock the pond, the colour
condition of your Koi will suffer as a result. Don’t overdo it!
Ik denk dat dit grotendeels ook voor goudvissen geldt.
Ik vond ook nog dit, geschreven door Rini Groothuis:
http://www.interkoi.eu/nieuws/column-va ... wetenschap
De koi in de Japanse mudponds worden gekweekt in zeer zacht water met voor onze begrippen ongekend lage pH, GH, KH en TDS waarden. Dat zijn allemaal groeistimulerende parameters.
De bezetting is dun. Er is veel natuurlijk dierlijk voedsel met een hoog gehalte aan goede eiwitten. De koi hoeft weinig energie te verbruiken om te eten en heeft geen voedselconcurrentie. Al met al bijdragend tot zeer goede groei.
Er zijn veel groene zweefalgen en andere voedingsstoffen aanwezig in het water, goed voor de groei maar zeker ook bijdragend in de kleurontwikkeling.
De watertemperaturen zijn in de zomermaanden hoog tot zeer hoog wat tot op zekere hoogte (afhankelijk van het zuurstofgehalte) bijdraagt tot een hoog metabolisme en weinig beweging (dus weinig energieverlies) van de koi, dus een extra groeifundament.
En weer denk ik dat dit ook voor goudvissen geldt. Dit is zeg maar 'het geheim' voor een optimale ontwikkeling.
Deze worden ook vaak in soortgelijke mudponds met groen water en een lage kH gehouden.