rkilling1 said:
That list was just a quick response, not a whole list. The GW should have had a NO3 to PO4 mismatch instead of just low NO3.
I've never been able to do this with every sort of PO4/NO3 ratio.......ever, nor have a dozen others.........
This has been going on for well over 10 year..............
I think it's safe to say this can ruled out............
I see no controls, few aquarist ever do controls or attempt to show causation, ....merely correlation at best without controls.............
There might be a few aquarist out that do, but I've not met many, I think I can count them on one hand.
Green water is related to iron, but only as all plants need iron
for growth. Right there is where I must differ in opinion.
Please entertain me on your "iron theory" here.
I've been extremely liberal with Fe for well over 15 years now.....never have I again, ever been able to show this nutrient plays any role in a tank with plants that relates to algae of any sort, much less GW.
I've used ETDA, DTPH, Gluconate chelators etc
I think based on your theory, I've been adding perhaps 2-20x as much as you suggest for nearly 15 years on clients, my own personal and other folks' tanks.
Where is my GW?
Why cannot I not show any GW for all my hard work?
Green water seems to grow, but only when the conditions favor it over
other plants. In aquariums where nitrate is the limiting nutrient, and
phosphate is in excess, green water (unicellular algae) does great.
The question is what causes a GW bloom, not where it does great.
It'll do great in many situations once you have bloom(That does not tell you much).
Both can be un-measurable by test kits, and here is why: With nitrate
being limiting, this asserts that everything else is present in larger
quantities. Phosphates only need to be in slightly higher quantities.
They can still be below test-kit range be being used up as soon as
nitrate becomes present, even in the most minute amount. In addition to
a constant presence (however low) of phosphates, the depletion of
Nitrates puts the higher plants at a disadvantage. Higher plants are
better at competing when nutrient levels are more "balanced".
Do mice and elephants compete for food in Africa?
Both are herbivores.
The Alga, this one in particular is about 2-3 microns across, very motile, can live on less than 3-8ppb PO4(The best reslution has an error of +/- 5ppb.
A plant?
Huge, billions of cells, often has roots, has much more defined boundary layers for diffusion, much much higher nutrient demand.
Even the best low PO4 plant can only handle 20-50ppb possible removal range.
That's as good as you are ever going to get with a plant.
Sorry, you are comparing two organisms that exists in vastly different scales both in time, sexual reproductive cycles and simply put, size.
It's like comparing one person to a contienent of people.
These two organisms are in two entirely different ecological niches.
The plants clearly need far more PO4, NO3, Fe to survive than GW ever does.
You need to ask a better question that is much more likely:
What induces the growth in the presence of plants that are otherwise doing well?
Add high light(faster response times)
Add NH4 over a wide range
Add progressively more and more fish
Add urea over a wide range
Lower /vary CO2 in conjuction
So now knowing that having nitrate being a limiting nutrient supports
green water growth, it is easy to eliminate it without filters,
additives, medications, etc. Just add nitrates to the tank (KNO3 works
well). By SUSTAINING a low level of nitrates (3-5ppm) in the tank, you
force the nutrient balance to shift. This will cause phosphates to
become limiting. Given time, this will cause the plants to thrive and
green water to fail. Be patient, as it does normally take a little
bit.
2 months?
6 months?
No one has solved it with this method I've ever met.
Nor has anyone induced it this way I've ever met.
A lot does depend on how turbid the green water is, how many
plants you have in the tank, how much you fertilize (and what you
fertilize with), and the bioload of the tank.
This would also explain why some tanks just seem to "automatically fix
themselves." Here I would suggest that the biomass has contributed to
rising levels of nitrates, causing the balance shift I talked about."
read the whole article here:
http://www.thekrib.com/Plants/Algae/green-water.html
FWIW, this is not the only source I have read this from.
That's some "old stuff".
Lower light tanks seldom have GW issues, higher light tanks cannot get rid of it for months without UV/diatoms filters etc, many have tried, and failed. Daphnia works well in low light tanks also, so do blackouts.
But those levels teeter on the light levels for GW to grow, the rate of growth is much lower, at higher levels, the GW is far more agressive, at poor CO2 levels, the GW is also much more agressive.
I've gone through and made sure that PO4, NO3, K, Fe etc did not cause/induce spores to bloom.
NH4 was added and this induced a bloom in 30 hours, pea soup in 48-72 hours at .5ppm at 4w/gal.
10 ghost shrimp per gallon also had the same intensity.
As did similar urea dosing.
The same tank was limited with Fe/K/PO4/NO3 individually with no impact at all on GW, large water changes, no impact either, higher fertilization: no impact.
Still have never been able to induce GW with any combination of NO3/PO4.
So if that causes it as you suggest, where's in my GW bloom?
I know I can repeatedly induce GW with the above methods, but cannot with the suggestions here.
Regards,
Tom Barr
hosphate ratio was not near the 10:1 it should be - it was more like 50:1 8O . I simply corrected the imbalance, and the green water went away in about 5 weeks and hasn't come back. 
