GDA: observations from a client tank

The recent redo of a 350 Gallon tank has often led to many good test to see, even if "mistakes".

The initial bloom about 3-4 weeks into the reworking of the tank= GDA bloom. A few extra water changes and cleaning, it was gone and did not return.

Well, till I came in today.

I looked under and what did I see?

Empty CO2, look like the tank had been empty for a few days. Light was low, about 40 umols, so it was not a serious case.
Switched the tanks out, cleaned things up, Swapped the canister filter(it was clogged as well) with a newer larger pore media, trimmed and when I go back the next week, do you think I'll see GDA again?
Why/why not?

What does this imply?
Autodosing, plant biomass was also pretty high, I did not trim last week. Light was/is the same. Filter clogging is one variable in addition to CO2........

Filter clogging (canister is an entirely separate and independent filter system vs the main wet/dry filter) and CO2 running out are the two main variables.
I've seen this in the past with BBA. I addressed this BBA by adding some Excel to the autodosers. So the plants still have some Carbon backup, so "poor poor growth" is not a factor, nor BBA which is much more annoying to me.

I've noted this before also about moderate/temporary to poor CO2 being the cause for various green algae and really bad chronic CO2: BBA issues.
We might say the canister filter was removing the GDA until it clogged. But prior? The Canister was taken off line for 2 weeks as it kept clogging. No GDA, so there was a control for the canister. We know Excel will do nothing to GDA.

 

Yes, agreed, my experience as well and the test I did is also supportive of that. Excel dosing alone did nothing to slow or stop it from what I saw.
Excel might help prevent the BBA some and help the plants grow okay till the CO2 tank gets swapped out later the next visit I come by to check(client does not do that at all here).

 

Yea, but CO2 still seems to be the main throttle to get the GDA going. I've seen little else that can do it.

The fix will be realized once I go again next week.

 

Yea, but BBA is easy to kill off, GDA is not so easy.

The cleint's tank also got BBA, but.........it stopped dead in it's tracks after the c/O2 was corrected. This latest case, there was no BBA bloom.
I guess the shorter CO2 issue was not enough to induce BBA, but enough to induce some GDA.

That's generally the pattern also: Milder CO2 issues: Hair algae/GDA/GSA/Caldophora
More serious CO2 issues: BBA.
CO2 plus organic loading: Green water and Staghorn.