[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: NO3 and PO4 in Takashi Amano Aquaria

John T. Fitch wrote:

>>If something was lost in the
translation, perhaps Karen Randall, the editor of TAG, could ask Mr. Amano
or his translater for clarification.<<

Sorry for my slow response on this one.  The translation of the nutrient
related parameters in the articles that appeared in TAG is correct.  ADA
told me the following:

"As far as PO4 readings of  0 mg/l is concerned, this has something to do
with the accuracy problem of the test reagent that we were using in the
past.  This particular reagent is capable of measuring PO4 in the range of
0.2 to 10 mg/l.  It detects PO4 when aquatic plants are not taking up PO4
very well such as when a tank is just set up.  However, when aquatic plants
start absorbing PO4 rapidly, PO4 would no longer be detected with this
reagent.  There was a period we misjudged the PO4 level to be 0 mg/l because
of this condition.  However, since PO4 can be detected with a more accurate
reagent, we now use the notation of <0.2mg/l when we can barely detect PO4
level with our reagent.  If an aquarium has a large amount of aquatic plants
growing very well and has very little algae, the PO4 is often below the
level our reagent can pick up.  Of course a more accurate reagent can still
detect such a low level, and therefore it is unlikely that PO4 would be
zero, especially if fish are being raised in the aquarium along with the
plants.  We find no problem with the growth of aquatic plants even when the
concentration is at such a low level.  However, if fast growing plants with
a higher level of nutrient uptake, such as riccia fluitans and stem plants,
are grown in an aquarium without fish or with just a few fish, we add liquid
fertilizer that contains PO4 and Nitrate.  For other tanks, we use liquid
fertilizer that contains mainly potassium, iron and other trace elements.
Generally speaking aquatic plants grow better when the levels of nutrients
such as PO4, NO3 and K are abundant.  However, since algae grows better in
such a condition, we maintain PO4 and NO3 in water column as low as
possible.  If some fish are kept and fed every day, PO4 and NO3 would not be
lacking in our opinion."

Hope this helps.  If you have any more questions regarding this, please let
me know.  I'll try to get more clarification from Mr. Amano.