I clean, I prune...and excel doesn't do squat on it...I am not even sure that is what it is. I really need you to check out the thread I have linked and look at the pics and tell me what you think it really is.
Note, the plants are clean, and I do not have any algae.
That's a soft green spot algae from the looks of it.
I've seen it in some tanks. I have gotten it if I do not keep up on certain tanks, generally those with low biomass.
Other tanks never get it.
Excel does not do much to this one either, I tried it a few times, nothing serious as the alga is not that bothersome, good cleaning and water changes every week seem to address it, if I slack or otherwise neglect something, it'll show up here and there, but only in some tanks.
This presents a real problem for many.
I have pretty similar tanks, other than plant biomass, same species etc, tank size, but the dosing, etc is pretty much all stable.
This shows how you can get many differing results from very similar set ups and dosing routines..........
But how some might think it's all the dosing.
There are many things other than dosing, that was kept pretty constant in this case, same deal with GDA.
Some tanks just never get it, the ones I tend more often and have higher biomass etc.
When folks on line compare their tanks, often there are large plant biomass differences and results.
That's not everything, but it is very suggestive of the variation we see and why we should be careful, before ascribing blame to nutrients alone.
Light and CO2 and plant biomass, species type etc play roles also.
I can rule out nutrients, light as those are fairly easy to maintain in stable range, easier than other things like CO2 or a moving target like plant biomass which can double in some tanks weekly.
So ruling those out first is straight forward. From there you go after the pruning, the plant biomass, filters, water changes, KH, plant species, etc.
Tom, I dose EI religiously, my CO2 is 37ppm I don't have a single unplanted area I do weekly water changes, and this tank is never neglected. Now what? The stuff is like a waxy gel. I only let it grow out over a three day period to take this picture. It is very hard to clean because it is so waxy, and there is no algae of any kind on my plants.
As for my KH it is 1 out of the tap...I like soft because my Tonina is happy in it, so I do no alterations.
also, there is no way I have a plant mass issue...there is no room for my fish to swim anymore...lol not to mention the duckweed that someone infected me with. That alone is a nutrient sponge. Take a look at the picture again...do you see a plant mass issue?