Happi, among many others, have struggled with Green Dust Algae for months etc. No real mechanism for inducement has been found. No real solution for control over the long term has really been found that's acceptable to many.
The few times I was able to get it to grow, I came up with a leave it be approach for 3-5 weeks, then wipe it off and clean well etc after it starts to slough off good. This worked for many, but also did NOT work for many other folks.
Sewignalot speculated that there was an interaction between BGa and GDA, and thus used EM antibiotics to help clean/remove the GDA also. This again, worked for some, but not all.
Due to the issue of inducement and not knowing how to do this, I felt it might be best to see if you can come up with a control measure that works in worst case scenarios.
So I chose a tank I recently broke down and removed all the plants as I'm undecided what to plant with just yet. There are a few plants, but no one in their right mind would call this tank low light or heavily planted. This tank was brown and green about 7 weeks ago. Walls were covered with algae.
I've not touched the glass since then and I added 20 small 2" long bushy nose plecos. Algae was gone in 1-2 days.
I have an ATI light and have PAR readings about 130 along the sediment and about 450 in the middle at the surface. Not many will more light than this.
I took the CO2 off line for a month also. No change in the algae, but after adding the CO2 back, the few remaining plants have grown better, so I've left it on for the last few weeks. Water change once a week, dosing modified EI 2x a week.
With this much light, no CO2, no plants to speak of.......plenty of ferts, ADA AS......where is my algae?
This is pretty much a worse case scenario, but there's no algae, there's some slight Green spot algae, but you have to look closely, the Bushy nose do not remove this, but no algae eater does really. But, there's no glass algae otherwise, no GDA, not diatoms etc.
So.....I decide to add the bushy nose in mass to a client who had issues when they increased lighting with GDA, many experience this light intensity relationship.
More light= unmanageable GDA.
Less light= manageable GDA
But, you cannot use the full light power..........
So I doubled the light and added the plecos, and..waited for the call about algae. Have not came, in fact , the glass is cleaner than it was with lower light. So is the wood and rock, equipment etc. Tried it a few other folks, same result.
So what am I looking for and why am I'm posting this specifically?
To see if anyone can show that the small Bushy nose plecos at 5-6 per 20-30 Gallons of tank cannot control the GDA issue
. They are cheap(less than many Amano Shrimp prices), peaceful little plecos, hardy, etc.
Better them than you.