He has three 150w MH basically sitting on that tank, and after one week the glass is solid green and you don't think the light has anything to do with it?
Well. this poster has it in the normal FL's as well.
You explained one, but what about the other lower light tank?
It will grow faster, but it's presence absence is not defined in/by high light.
But that is true for most algae also.
So that is
It's based on my and his observation/s.
Telling him that is not going to help, being slothful is never the correct answer either, I have never had to look at any of my tanks with fugly green walls for weeks or more because I didn't understand that the light was causing the problem.
You assume that it is, but observations suggest that cannot be the only
factor, it does occur, as much as you might not want to admit it, in low and high light tanks.
Rate of growth is not the question here and that's about all the light is really doing here. GW is similar, it'll grow much better/faster, produce more biomass in high vs low light.
And in most cases, you can get rid of all algae in lower light easier.
I think that might be your point?
I agree with that.
There are other factors involved yes but without the light the glass will not be a solid green in a single week.
So what might other factors
will be influenced once you reduce the light? CO2? Nutrients? Growth rate?
You can stop algae with blackouts, but this one really does not work too well, but you can do it and say it reduces the growth rates(it does, and for plants as well).
Of coarse it is each persons choice to burn that much light that it creates a mess but the simple fact is plants do not need that much.
Oh very very true, no disagreement here, we are certainly thinking the same.
It does does afford far far more wiggle room. Been telling folks this for decades, but no one listens to that part
The problem and unsightly tank can be fixed and almost pleasant to look at again within one day not weeks or more.
I suggested that method
as well, as well as the lower labor method of patience. I've been able to beat every alga inside a week or less.
Cleaning it off, daily, or even 2-3x a day, large water changes, Excel after, micron filtration and UV mix, high filter flow rates to get it all, making sure the other parameters are in check(lowering light will give more wiggle room, but if you use high light, you should try and tweak the high light you have, I've not had issues with that, the rates of growth for plants and algae are higher, so response times are faster and if you failed in the eradication method, you'll have a relapse much faster and easier)
Add strong pruning, fluffing plant's leaves, add some herbivores for cleaning the plants etc, you and most folks should be able to do it.
Now while I can do this 12x out 12X, other folks will not be able to even if I tell them everything, the likely hood they will get the parameters alone correct suggest 90-100% success is not likely. Too many variables.
Some cases you do get lucky with amethod that works well and has higher success rates, blackout with BGA works 100% if you follow directions.
It does kill it.
Same deal here, you can remove and wipe it off, then run micron and UV, water changes harass it enough selectively, but that also drives plant growth a lot as well.
However, if we look at the observations about light with folks that do have it, light is a not large factor, e.g., folks only with high light do not get it.
you'll need to explain that and how high light is really the driving factor here.
Your own hypothesis: high light only = Green Dust Algae, is falsified, not only by others, but within this same hobbyists tanks.
If you changed the hypothesis, to say high light = faster growth rates of GDA, then you have something more reasonable and workable. I've measured this many times in the field.
I do agree most species of algae can be beaten simply by using less light and are easier to beat.
I also agree folks, this one included do have too much light for the levels of care many put into the tanks they have, they'd be better suited using less light.
But the control of this alga does not appear well correlated with light.
I have a tank with MH's, PC's and a heck of lot of light and it's been subjected to GDS at least 20 times now with GDS inoculum.
I have never been able to get it to grow in that tank, ever.
I have a smaller tanks with a pair of T5's, I had it going really good.
It had 4x less light, one had 450 micromols, the other 110 micromols of light.
Based on that, I have trouble saying light in a large part of the variation in observations.
Does this explain why I said what I said better?
Adding less light might help, but it should not define why they got it or have it. I'm not certain why this alga blooms when it does and how.
I've never been able to induce it consistently enough to have any confidence. But I do know I have tanks with lots of light and no GDS, at least as much as this tank in question.
But more to your point, suggesting less light by raising them up is wise as well. Agreed.