So, mineralization of phosphorus-containing organic compounds ideally ends in the form of orthophosphate, indeed, but you can seldom find any...
For anyone who is allergic to science, you may be wise to skip what awaits you below...
I have no difficulty detecting orthophosphate, i.e. PO4^3- in my tanks. The JBL Phosphate Sensitive
Test Kit measures down to <0.02 mg/litre. I also have a Hanna HI713 Colorimeter which measures down to 0.05 mg/litre. I have accumulated a lot of papers, etc, related to this topic. Here's one that you may find useful:
Bacteria are central to the cycling of carbon (C), nitrogen (N) and phosphorus (P) in every ecosystem, yet our understanding of how tightly these cycles are coupled to bacterial biomass composition is based upon data from only a few species. Bacteria are commonly assumed to have high P content...
Whilst on the topic of phosphorus and bacteria, you may find the following to be interesting. It's taken from the irreplaceable The Krib
. It's a discussion group before the days of forums:
I find the following to be particularly useful:
All four sections in 'Phosphorus and Phosphorus Control' are well worth reading - in my opinion. Here is an example:
Phosphatase is an enzyme that bacteria use to convert DPo* and PPo** to
DPi.*** Some algae may also have that ability. Alkaline phosphatase - which
works when the pH is near and above 7 - is the most well documented form
of phosphatase. There is also an acid phosphatase that doesn't seem to be
as well documented. Phosphatase activity increases with the size of the
bacterial population; activity is promoted by oxygen and suppressed by
Bacteria typically produce more phosphate than they consume, and that can
lead to an excess of phosphate in the water.
The phosphatase-catalyzed reaction from PPo to DPi should be discouraged
to prevent production of excess dissolved phosphate. If the reaction can
be slowed down then phosphorus will remain in the detritus where it can be
more easily siphoned off before it causes problems.
"The conditions that promote high levels of phosphatase activity and so cause
rapid release of phosphorus from detritus are exactly the conditions found
in aquarium filters. In a filter, organic particulates are trapped in a
constant flow of aerated water where a large population of bacteria can
act on the detritus. The flowing water also flushes the phosphate
released by the reaction, which otherwise could suppress further
phosphatase activity. So removing a filter should reduce the phosphatase
I keep unfiltered tanks. I think in retrospect that pulling the filters
off my tanks helped control phosphate levels, but I can't substantiate
It will be interesting to get feedback from UKAPS members on the above. Do people agree with the points being made by Roger S. Miller and others?
I am really keen to hear what UKAPS members have to say. My stance is neutral as a lot of what is being said is new to me.
*DPo = Dissolved Organic Phosphorus
**PPo = Particulate Organic Phosphorus
***DPi = Dissolved Inorganic Phosphorus
Now, give yourself a well-deserved pat on the back if you've managed to read this far!!