Makes sense if you focus only on plant growth - as I know you propose. Mg could be limiting plant growth and giving GDA a foothold, I think the arguement goes. However, my plants always grew incredibly well during the GDA outbreaks and when I did scrape the glass I would see my overgrown jungle waiting for a trim. Didnt slow the algae growth.
Does not imply that there's a slight Mg limitation or not.
Plants still grow with various levels of limitations with all sorts of nutrients..........
As we've seen with other types of algae, there are certain predictable water parameters that bring on certain types of algae. In my tank, if I let Nitrate drop below 5, I know I am going to start seeing BGA. No other types of algae appear. So, according to the plant growth focus, my plants must be growing more slowly and allowing algae to take hold - but why only BGA? Why dont they all come on at once at this point?
Why do we have more than one singe species of algae?
To me, this supports very strongly the idea that, while healthy plant growth may inhibit algae, it cannot stop all types of algae. Also, there are certain nutrient threshholds that must be met for the ever present algae spores in our tanks to bloom into visible algae.
The nutrient centric thing has taken more and more folks down this path to myths than I care to count or recall over the years. FEW hobbyists have done good testing or research here. I'm none too confident.
I know that plants dont know math and ratios are laughed at, but we do know that certain excesses of nutrients in the water column create plant deficiencies for other nutrients,
We do not know this. Name one.......that is the range we might see/experience in an aquarium.
I know of none. It is not like I have never looked either.
even if the other nutrients are present in the water column. How then is it unreasonable then to think that certain levels of a nutrient in the water, relative to another nutrient would INHIBIT ALGAE GROWTH (not increase plant growth, inhibit algae growth - big difference)?
Errr..........cause it's easy to test a ratio and it is ALSO easy to test individual concentrations, and vary ratios all the place, but well beyond potentially limiting concentrations?
Been here, done this.
Refer back to Liebig.
Basic stuff, you are falling into the trap of wishful thinking here, not basic plant science/horticulture.
Going one step further, how then would it be unreasonable to assume that a 'complex' relationship could exist that inhibits GDA?
See above.........no need to keep pushing for complexity when the basics are not understood or addressed, go for the low picked fruit 1st........then maybe...........once mastered, then folks can try to test the more complex relationships.
Generally by then, their level of horticulture is sufficient not to worry much about algae.
I'm curious myself, even if it does not present an issue for me. I like algae.
Meaning, that GDA will not bloom unless there is an excess of Ca vs Mg OR an excess of N to P?
This sounds like mumbo that some folks believe and I have found zero evidence for support, both research and the aquarium settings with a control reference tank.
You need to the control tank to see. No control, no test.
It's that simple, there has to be verification.
In this case, changing and monitoring one variable at a time may never lead you to the result you want. Ie if your N and P ratio is put of whack and you are just adding Mg, you could get your Ca:Mg ratio inline, but becuase your N:P ratio is still of whack, your GDA does not go away. You declare your Mg theory debunked and go on to test N:P and your Ca:Mg drifts back to out of whack. You get your N:P ratio right, but stil GDA becuase you're no longer considering Ca:Mg.
Could be, but how do you plan to show this and back it up for each and every case?
I've gone all over the board with Ca/Mg and with NP ratios.
Mostly to illustrate that they are meaningless
Liebig showed this as well. I'm not going against that.
I just suspected Mg since it's one of those more forgetful neglected nutrients/folks rarely test etc, make assumptions about.
More complicated still would be some combination of absolute minimum level and ratio (ie Ca:Mg must be no more than 3:1, N:P ratio at least 10:1, Ca no higher than 40ppm, and P no higher than .25 ppm in order to prevent GDA bloom, for example).
My Ca was 80ppm and my PO4 was 20X this, no issues.
Inoculated many times.
Likewise, I had 12ppm Ca and PO4 at 6=9ppm and no GDA.
How about 1:1 ratio for Ca:Mg?
How about 20:1 Ca:Mg?
I did not try limiting Mg strongly over time.
This stuff might take 8 weeks........or maybe only a few days to germinate.
It might be more with light and CO2.........
I do not believe the ratio baloney, I just have never found a hill of beans worth of evidence for support.
Possible sure, evidence or test? None yet.
Solution is to change and track multiple parameters through multiple ranges and see when you get GDA (maybe more even than just Ca, Mg, P, and N - I suggest these only because the MCI author proposed them based on his experience and they are the two i monitored and changed to eleviate my problem - could be more involved and i just got lucky). I suggest the reason we've not as a hobby solved this one while other algaes are more easily controlled is exactly becuase of some kind of complex relationship between the parameters that cause it.
That guy is nut.
Have you seen his tanks? Ratty AND High light.
There's no controls.
Aside from somone taking a few weeks, and tracking all parameters through all ranges in a few quarantine tanks, we'll probably need to keep tinkering and collectively building a model. But one paramater at a time may not be the answer and focusing on strong plant growth as opposed to algae inhibition will only miss the mark.
It's worked a lot better than the other methods with multiple parameters.
Stepwise, careful progressions have led to a better understanding for BBA, BGA, GSA, Staghorn and others. Name one multiple that's done us any good?
I do not argue they do not exist, but rather, argue we should look at the assumptions more and see if we cannot first rule out the simple easy low picked fruit. Only then, consider more complex stuff.
If you lack the fundamentals, how are you going to handle the complex?
Seems like getting ahead of one's self.
I have gone all over the place with ratios and dosing various things, I cannot rule out a few things and Mg happens to be one. I would not expect results in a week, maybe 2-4 weeks time........Then that might give an indication.
If the CO2, or other issues are present...then this might not work.
As the case with many folks, there's no control.
Bsmith's tank and plants I have some background with. So seeing if it's just Mg.....not a bad idea.