quite so Red. There are many ideas as to why green water shows up but it is
normally a deficiency of some sort.

No, it's directly too much NH4, this is the one thing that will cause
algae if it is allowed to get too high(which ain't that much).
NO3, limited tanks are common, so are CO2 limitations and PO4
limitations and Fe etc.

These tanks do not get GW. I can induce GW easily everytime with NH4
dosing.
I've NEVER been able to show this with limiting any of the above
nutrients except for NH4.

If nitrate is limited n a planted tank
and phosphate is too high from either dosing or overfeeding then green water
thrives.

There is one part here, the feeding. This waste is first NH4, hence
the GW, but if you isolate the issue(Remove the fish), and use
inorganic forms of NO3 and seperately NH4, then the issue becomes
clearer. I've done this for years. The results are the same every
time.

Correct this by cutting down on feeding and adding more nitrates
combined with water changes and the green water will disappear. On the other
hand , if nitrates are not limited but are out of balance then green water
also thrives and nitrate dosing must be cut back.

No, this was not true either. I went to 75ppm of NO3 in effort to
induce GW, no green water after over 3 week peroid.

Few people have ever solve their GW issues through water changes even
after 6-12 months.Your plants will die of starvation before you beat
GW.

It is simply a matter of
checking different things to find out the solution. U.V will eliminate green
water as it kills the free floating algae however if the reason for the
green water is not corrected it will always come back.

Generally it's due to the substrate disturbance and a temporary spike
of NH4.
If the fish load is too high or the plants are limited(hence
indirectly do not take up NH4) then this will also cause a longer term
issue.

UV's are my method of choice, but are not cheap.
Hagen quick Filter are 5 microns ad can be used. So can the cheap
pleated cartiages that fit the 9 3/4" filters they sell at Lowes, Home
Depot etc for about 20$ for everything, add a powerhead or filter etc
to that.
Diatoms also are great.

If you have lower light, generally less than 2.5 w/gal or NO FL's and
not CF's, then you can use the blackout method fairly well.

As far as decaying algae, haha....come on....that's plant food now and
the biomass is tiny if you filter out all the GW you could and saw how
little biomass is there, it's very small and rather insignificant in
terms of decay.
Most do a 50-80% water change prior to shock the algae some and remove
some of it's biomass.

Average size of GW is about 2-3 microns. So 5 micron filtering works
well after it clogs a little.

Regards,
Tom Barr









Rick