Even if the PO4 test is correct, your enmtire assumption about the
cause(not the correlation) of PO4 being the root or even the
contributing gfactor to BBA is flatly wrong. This was shown over a
decade ago both in the USA and in Germany.
We limited the PO4 to less than 0.1ppm, which is about as low as any
decent test kit can go, which was a Hach and a Lamotte test kit and we
used KH2PO4 for standards to check if the test kits where accurately
reading.

We found no corelation between BBa and PO4 levels, if anything, there
was a strong relationship between higher PO4 levels and lower presence
of BBA.

In any event, folks routinely on most popular aquatic plant forums and
boards add KH2PO4 to maintain 2-3ppm of PO4 through the week. They have
no BBA. I've been adding PO4 for at least 15 years. I have no BBA.

Sio if you accept that high PO4 causes algae/BBA, where is my algae?
This hypothesis is wrong, this is a myth and has been said as such.

The information you got that is was caused by high/excess PO4 is very
outdated, 20-30 years or more old and based on __myth__, not any
testing.

If someone says algae is caused by X, I add X to an otherwise healthy
tank, and I do not get algae, it's difficult to sugegst that X causes
algae.

If you want to stop BBA, learn how to use CO2 if you add that.
Low and variable CO2 levels are the only cause for BBA I'm aware off in
CO2 enriched tanks.
In non CO2 tanks, stop doing water changes and add enough to top off
for evaporation.

For the CO2 tanks, add enough to get about 25-30ppm and keep it there
throughout the day peroid.

That's it and you do not need PO4 removers, they will not help.

Regards,

Tom Barr

www.BarrReport.com