Na newsach znalazlem ciekawy watek, o zbijaniu fosforanow "stalową wełną w kulkach" (o ile dobrze to przetlumaczylem). Stal rdzewiejąc rozkłada się i wiąże fosforany
Słyszal ktos o tej metodzie?
Ponizej wyciag z dyslusji
----------------------
I treat Phosphates with small balls of steel wool every two weeks.
All I do is roll up a small ball of steel wool about 1cm in dia. and drop it
in.
The 1st time I did this the tank went a bit cloudy.....this is good as it
lets you know the phosphates are being binded.
Every 2 or 3 weeks I drop a small ball in. Every time I test for
phos........there are none. No other side effects.
By they way.....the steel ball 'rusts' away to nothing in about 48 hours.
It is the iron oxide that deals with the phosphates. Nothing remains to
remove.
I have been doing it for 6 months.
Phosphates have not returned. Maybe I could cut the amount of steel wool
down or do it every 2 months????? I don't know. My local fish shop guru said
'do this' and I di it. He has never been wrong.
Quick googleing:
"
a chemistry question
Dear Mr. Bob Fenner,
First of all, I would like to thank you for answering my last question a few
weeks ago pertaining to Cyanobacteria. Of course your advice worked and was
appreciated. Now I have a new question of a little bit more technical
nature.
A year or so ago, I was in a chemistry class at my university and learned
that Iron would bond to phosphate in much the same manner that it bonds to
calcium carbonate and would precipitate out of solution. This idea appealed
to me very much and immediately went home to conduct an experiment. I set up
a ten gallon aquarium and with a whisper hang on filter. Then I filled it
with water loaded with phosphate. I am not certain as to how much phosphate
as it was off the scale of my dry tab test. Next I let the temperature
equilibrate at 78 degrees and inserted a fair sized piece of steel wool in
the
back of the filter. This is where it gets interesting. I checked the
phosphate again 12 hours later. There was no change but the water was cloudy
with a whitish sediment forming on the bottom. 36 hours later I checked the
water and it was devoid of any phosphate which my test would detect and the
water was clearing. I have since asked a host of professors from chemists to
biologists and even a geologist about the potential effects of either the
precipitate or the iron on any living organisms in the tank. Most of them
were willing to talk to me about possibilities but none could give me a hard
answer and all were too busy to look into it any further.
I have since heard of a commercial filtration system which uses iron as a
phosphate remover in addition to activated carbon but that was only in
passing
and I couldn't find out any details about it. I am hoping that you might be
familiar with this idea. I would greatly appreciate any information you may
be able to pass on as I am too poor to experiment with fish on my own and I
am
not very keen on wasting a perfectly healthy fish or invert by accident. I
hope that I am not just wasting your time or mine but this sounds like it
would be a cheaper alternative to commercial phosphate removers if it really
works.
Sincerely, Your avid supporter and Fan, Byron Toothman
>>>>
Byron, you raise many important (at least to me) and interesting points. As
a practitioner of the pet-fish arts and sciences as well as an ex-HS
Chemistry/Physics and Bio. teacher (and avid reader since on the subjects),
I am familiar with a bit of what you're referring to: Yes ferrous ion will
precipitate out phosphate (hydrolysable, about the only form pet-fish
hobbyists are concerned about), and No, most all the Phosphate removed in
this fashion is gone... made insoluble. But, a bunch of buts here... Both
some phosphorus and iron are necessary to all living things hobbyists
like... but not too much of either one... Not to be seen as trying to appear
elusive/evasive, there are other bits of the big puzzle to be lost by
over-supplying iron... in whatever valence state... and a few other reasons
(toxic ones at that) for avoiding this route... Instead, might I strike out
for truth, justice and the ornamental aquatics way and suggest neither iron
nor commercial phosphate removal products, but simpler boosted
photosynthesis as a/the means of removing excess PO4? Here's my usual plug
for "balance" twixt lighting, nutrients/feeding and purposeful Macrophyte,
live rock, algae scrubbers...) photosynthesis...
Bob Fenner "
"* In strongly acid mineral soils, soluble Fe, Al, and Mg can exist
and react with existing phosphates rendering them insoluble. Often
the amount of soluble metal ions greatly exceeds the amount of
soluble phosphates, and only minute amounts of soluble phosphate
will remain [for plants and algae] at equilibrium. Even greater
amounts of phosphates are removed from solution in acid soils by
oxides of Fe and Al. In acid conditions these oxides have a net
positive charge and they attract phosphate ions from solution into
exchangeable positions on their surface. With time the phosphate
ions either migrate into the center of the oxide particles and
become unavailable, or react with the hydrous oxide to form an
insoluble compound, or are use by plants and microorganisms. Since
several insoluble compounds can be made by the reaction of
phosphates with hydrous oxides of Fe/Al, it is thought that
phosphate may be fixed over a wide pH range extending from low
through the neutral zone, even though little charge exists in the
neutral/alkaline region on the oxide surface. Kaolinite can also
fix phosphorus under moderately acid conditions, but the mechanism
is unknown. Other silicate clays hold a very small pH-dependent
positive charge which is generally insignificant. [Hydrous oxides
and kaolinite are the primary components of tropical 'laterite' or
'latisols' (the more current name). This suggest that laterite in
the substrate with water circulation through it may play a role in
reducing phosphate levels in a tank, especially in acid water. It
also suggests that any form of iron oxide in the tank (rusting steel
wool in the filter or unchelated garden Fe supplement?) may help
reduce phosphate levels in the tank. Since a low pH is better,
substrate additions may be the best bet.]
"
