Help 3 week gda lifespan a myth?

[Jarno]

I read that gda has a lifespan of 3 weeks and if you leave it on your window for 3 weeks it will die but if you scrape it off before it will replant itself and the process will restart.

Normally i scrape it off before waterchange but since it keeps coming back im trying to let it stay on for 3 weeks.
But im doubting if its true.
My glass is completely covered now and it itches to scrape it off
I already did half of it during a 50% waterchange with paper so it would not get back in the water.

 

[SmartAlec13]

I have never heard that before, and I am willing to bet that is a myth. I would bet its a myth mixed up because of "startup algae", where new tanks often go through a few weeks of an ugly phase that mostly goes alone on its own.

This doesn't seem like just startup algae, instead I would imagine this indicates an imbalance between light, CO2, and ferts

 

[Jarno]

I have never heard that before, and I am willing to bet that is a myth. I would bet its a myth mixed up because of "startup algae", where new tanks often go through a few weeks of an ugly phase that mostly goes alone on its own.

This doesn't seem like just startup algae, instead I would imagine this indicates an imbalance between light, CO2, and ferts

Even chatgpt says it altough chatgpt is full of faulty answers.
You could be right about the new tank theory.

No haha not a startup algae for me this tank is 2 years old.
My co2 has a ph drop of 1.5-1.6 (6.7 degassed 24 hours and 48 hours / 5.1-5.2 saturated)
Starts 2 hours before lights go on and turns off half hour before.
Fertz are apt e (20mg/l no3, 1.5-2 mg/l po4) daily dose of 6 ml (daily uptake by plants) weekly dose of 38ml after waterchange.
Lights are 180 par at the bottom water is 50cm deep (8 hour total, 1.5 hour build up/1.5 off) , decent light but ive seen much stronger lights in tanks that had no algae at all .
Meanwhile im struggling 2 years to keep my tank in balance

 

[TRyan]

There's an imbalance of fertilizer/light//CO2. That's a lot of CO2 and high light. Definitely not lacking there. My guess is it's not enough fertilizer to match the amount of CO2 and light you have.

 

[Kwyet]

I read that Tom Barr said this, that the life cycle is about 14 days and if you leave it alone and don’t dose ferts then it will go away. Maybe he can comment, because it was a long time ago. @plantbrain

 

[Koan]

Tom Barr said this

@plantbrain talked about life cycle for this category of algae, from spore to maturity to senescence

Here's the long discussion at Barrreport:

Green dust algae and herbivores

 

[Naturescapes_Rocco]

I've tried the wait-it-out-then-remove method many times before. It almost never works IMO, as GDA is sometimes a sign of imbalance. Specifically I notice it when I have very little micros, very high macros, and high light. If you wait, let it grow, remove it, water change... it will probably come back.

I often consider my tanks close-to-balanced if I have zero GSA, zero GHA, zero BBA , zero BGA... and some GDA on the glass.

If your plants are 100% healthy and the ONLY algae you get is GDA on the glass by the end of the week, well... as long as it's not too bad or too annoying to clean up, that's pretty well balanced. I get a thin film of GDA on my glass at the end of almost every week, but it's THIN and barely noticeable from frontal view.

So I'm +1 on @TRyan's assessment; usually just too high light. Sometimes a sign of imbalance, too, but if it's just a slight amount over time well, that's hardly an issue if your plants are healthy, too.

 

[TRyan]

I know there's a few people on here that successfully run CO2 with a 1.5 pH drop, but that seems to be the exception. 1.5 -1.6 pH drop is a LOT of CO2. I'll wager that's well over 100 ppm.

You could try lowering your injection rate a bit and keep light and ferts where they're at and see if that helps.

 

[Jarno]

I know drop checkers arent ideal of measuring co2 and the colours almost look the same having a lot of different levels.
This is a 30mg checker but i doubt a ph drop of 1.5-1.6 is really accurate even tho my ph controller (not connected to the co2 injection) says it does. I think the soil affects the ph when being in contact a lot. While my co2 free water rises a lot due to not being in contact with soil. But i could be wrong. What would make sense since every experienced aquarist says ph is the only right way

 

[Pepere]

I have no idea…

But, I did have GDA for a while and would scrub it off midweek with magnetic scraper and again at water change..

And after a while it diminished and went away. No real action on my part that accounted for it.

I figured my plants were growing well and they didnt have and GDA forming on them and no other algae was growing anywhere. I figured I could scrub the glass twice a week .

It was self resolving…

 

[Jarno]

I will reduce co2 to 1.4 to see if i get a postive affect