The same applies to <"
GSA and raising PO4--- levels">, I don't know why it works, but I'm willing to accept that it does.
I think you nail it in <
this post >; certainly without extensive testing, we cannot say for sure. However, after my experience with extremely <
out-proportioned potassium >, I have to say that I have accepted cation interference - which is all grounded in concentration gradients of nutrients. Every post I read that has GSA is from EI users. When I dropped potassium, my GSA on the glass didn't come back, nor did it continue to get worse on my unhealthy buce 🤔.
If we follow Mulders (and I chose to add the one below fro MSU, though I see some different ones - which is unclear to me - where the antagonism are not the same):
Zinc, Copper, Iron, Potassium all inhibit phosphate. Think of the EI trace dose - I've got no numbers - but it's well over what the tank needs (as it should be in the spirit of EI).
note:
1) We can discuss here ion exchange INTO the substrate.
2) We can also discuss source water.
3) Light - HIGH light means more nutrients (including CO2) are being absorbed).
Is it possible that the micro nutrient accumulation (and in every tank is different due to 1 and 2 and 3) over a period of time inhibits phosphates. It is certainly not day 1 or 10 or 30 that gave rise to GSA (at least not in any tank I have ever had - albeit not that many - or in posts that I have read from a variety of forums) ... it is later. It is only after a period of time that the higher phosphate dose is needed. We know nutrient accumulation with consistent water changes will plateau after several weeks ... that plateau is the baseline and it is at that point we see GSA pop up ... as a result, we need more phosphate to overcome the baseline of nutrient accumulation (I am not talking toxicity).
The deficiency of phosphate in the plant is not SO large that it is demonstrating dying leaves but it is large enough that pockets can have GSA. I mentioned in that excess potassium post that:
Interesting note the excess potassium did not allow algae to attack my fast growing plants - even Ludwigia (which is slower then rotala), s repens, etc. However, my unhealthy buce was having a persistent issue - it seems that the leaves look like they are getting better ... I wonder if that tiny micro nutrient (forced) deficiency was enough when compounded with slow growing to make the plant weak enough for algal attack. Interesting.
Then, <
here> , we see that
@tiger15 said, "Even healthy plants apparently free of algae have micro algae if examined by a microscope. "
And to what extent that algal concentration is, is likely a barometer for how "close" we are to meeting the "perfect" ratio.
With regards to an aquarium system, in agreement with Tom Barr in that concentration rather than ratios, light intensity and availability of Co2 all marry to create the potential growth capability of the plants in that system.
I am quite interested as to what is the difference between concentration rather than ratio. I am seeing ratio as relative concentrations.
Further, I think we are discussing water column concentrations, which are independent of substrate - if you use inert substrate, then your WC is a true indicator of what you have; however, we cannot say that the plant decides to use the water column over their roots at a particular moment in time - though I would love to sit down and drink coffee with Rotala to discuss the choices he/she makes.
What we can say is that higher nutrient column fertilization compounded with flow increases the probability that the plant will be able to come in contact with a nutrient - hence higher concentrations of everything "ensure" that the plant will come in contact with what it needs --- that means higher concentrations in water and/or substrate. This movement happens with concentrations (I have no link, but it must) and necessarily charges - hence too much of one HAS to inhibit something else ... leading us to relative concentrations (which is ratios).
I like what Tom said, "If you I have a ratio of 0.01 PO4 and NO3 of 0.16, I can promise you, plants will not do well," but I think it is a probability game now instead of actual nutrient availability. If you took a plant and over each leaf you had a probe with an injector that maintained this ratio NO MATTER WHAT (i.e. a response to trigger a dose when the probe reading changes) - it would have to grow as you are not limiting anything.
Back to GSA, I think we see tiny pockets of phosphate deficiency (as long as CO2 is good - remember too much phosphate increases to nutrient requirement of everything and as a result can give rise to CO2 deficiency) that GSA inhabit - why GSA ... beats me, but they must be able to uptake a particular nutrient easier than other types of algae. Why it's tiny pocket - because there aren't too many traces
😛.
Please note that I have not changed my traces in my post above only potassium (which is in much higher concentration than the traces that I just suggested) and I saw a huge decrease in GSA.
These are all my thoughts and I have no evidence, but my intuition says that somewhere in here, we have a thread to why GSA and low phosphates correlate.
Josh
