zenkatydid said:
After being a member of this forum for some time, I am pretty convinced that BGA is caused by low nitrates. However, try and explain this to anyone else, and they laugh at you and call you evil for even suggesting such a thing. Everyone else seems to think that BGA is caused by high phosphates. What is right? I know that Tom Barr has done studies on this sort of thing, but is there any papers or official studies that I can point people to as proof? What can I use as an argument when confronted with this? And also, does the low nitrates thing only apply to planted tanks? What is the case with non-planted tanks?
Thanks for your help
Tell you what, ask them to show that it's caused by high PO4, any algae for that matter.
1.
For cause to be shown, you must maintain non limiting parameters of the individual nutrient in question.
2.
You must have enough control to have an algae free tank to start off with.
3. If high PO4 = algae causation, then why don't thousands of folks who do add high levels of KH2PO4 have algae?
No#3 cannot possibly be a cause regardless of other parameters, test kits/method etc. For that to be true, we must have all observed cases have BGA, this is far from true.
I've set up hundreds of tanks over the years and never had it until we started lowering NO3 specifically.
My PO4 levels have never been below 1ppm and typically are 1-3ppm range and have been for the last 15 years.
If high PO4 causes algae, where is my algae?
I suggest that anyone interested try this, lower just NO3 and have everything else higher and see for yourself.
Then you'll know.
It takes awhile, maybe a week, few days, sometimes longer.
But it does appear consistently if you inoculate the BGA.
Raising the NO3 back up prevents reocurrance even if inoculated.
Those are the observations........you can conclude what you wish.
Regards,
Tom Barr