Green dust algae and herbivores

I've recently been able to induce Green dust for more than a week or two.

I did this by using newly redone tanks without some small little critters and by removing some killi fish that appear to be eating the critters.

These are small aquatic herbivorous insects or perhaps the herbivores are smaller and these are eating the actual herbivores, I have not identified the insects or the possible microscopic insects.

But......after leaving the GDA alone for about a week, the population appeared to grow rapidly, then the green dust went away and is only in high current locations.

There are cherry shrimp in the tank and they appear not to eat the insects.

I wondered why I never had GD for long, I've tried to induce it many times.

When we wipe off the GD algae, it'll swim around and attach again. we keep repeating this cycle, it'll never go away easily.

But........if we just let nature take it's course, and let the GD go to the sexual spore stage and die off or be eaten by these critters, then it'll go away on it's own and not return.

By continuing to disturb the algae and the cleaning the glass, we perpetuate the the problem actually.

I've noticed this same pattern after leaving it alone for week or two back in 2000 and here recently.

I thought it was the shrimp maybe, some nutrient, maybe higher plant biomass etc, but just allowing it some time and in 2 weeks of good growth, decent plant biomass, some shrimp, it's gone away on it's own.

I think GD is a very poor competitor.
So it will colonice glass very fast and recolonize.

But you'll notice since we keep glass clean by cleaning frequently, we also provide a good place for the GD to grow without competitors.

After the GD dies back for 2-5 days, then you go in and scrub off the harder algae, then the GD does not return and you have low glass algae issues from then on.

The GD seems to need to go through this cycle and once done, should not bother you again.

Weeds will populate a newly tilled disturbed soil, but as time passes, these early succession weeds will die off and be outcompeted by more combative species or by herbivores, I believe this is true for the GD algae as well.

GDA will do well, as many early succession weeds do, with good non limiting nutrients and high light.

But as light decreases, so does GDA, likewise, as competitors move in, the GDa dies back also. As herbivore populations increase it appears that the GDA also backs off.

If you scrub GDA off, you'll notice where it resettles again.
Generally the lower flow areas and high light.

If you allow the GDA to stay awhile, allow the herbivores and other algae grow on the glass, the GDA will go away in the low flow areas and only a small amount will be left in the high flow areas(the flow blast the other herbivores away, but some algae can live there, eg green spot algae.

I do not have the whole process of other possible processes figured out, but I have enough information and observations to make some testable approaches. It'll take time, but GDA will go down like all the algae before it.

This ecological approach rather than herbicide/algicide approach is much better at solving the issues and understanding their causes.

By understanding the ecology and dymanics there, we can be much better at dealing with the control with or without the algicides approach also.
When dealing with weeds, simply killing a weed and then allowing the seeds to live will not be smart..........it's much more intregative that this and interwoven.

This packs a one two punch but the natural method should be used first, seems to work where algicides fail and it also addresses the plant health better.

All algicides affect plant growth to some degree, just like all herbicides will affact and lower crop yields also, the trade off makes it worth while for the crops though.

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

BTW, the reason I suggested the herbivores : there are many small herbivores crawling all over the tank where the algae is not now.
The only spots where GDA is present is under high current. Normally, that is the harshest place for GDA to grow due to high ciurrent, but it's also the best place to get away fro the herbivores also as well as good place since some algae is dislodged providing new, but safe substrate to grow on.

Wiping the glass clean might remove some of the slower growing more competitive algae and hurt the herbivore matrix, not allowing it to fully establish.

We know it's not nutrients because we have good nutrient levels, the same even, in tank with and without the algae. You can slow it down some with the nutrients/less light/less CO2............but not kill it off. There are other factors that appear to do that.


Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Yes, just let it be for a couple of weeks, I know, I know, hard to resist.
Crank the CO2.

The other approach, turn off the CO2 and the light for 2 days. Then still leave it alone, then wait 3-4 days and see it it grows more..


If not, then clean it off.
If so, leave it alone for a little while.

I need to figure out if these herbivores are the reason, the CO2(probably not unless it's a mild issue).

I had so much GDA that my surface was green and bubbly.
I might try not adding CO2 for a couple of days also, that seemed to work well also.

I clean my tank once and quickly vacuumed the water out, then durmped it in the toilet. I waited 5 minutes to flush and the after flushing, the bowl was green from the little suckers attaching to the bowl!

I know I'm not too far off from figuring this alga out.
Still a ways to go. But I have induced it and I have cleared it in several tanks now.
It's just a matter of time now.


Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Well, a window is a great source for GD, there's a definite relationship there.
I have tanks that get hit every afternoon and have for a long time. Two tanks have GDA, but some cured themselves so to speak.

I'm still not clear why the other tanks have the GDA still other than the Killifish picking off every critter in the tank(the tanks that are "cured"=> no killi fish). Plant biomass is very high in both tanks. Same size, lighting etc.
Not much difference.

The GDA is far from over, but I have a few ideas to work with now I've manged to grow the alga in multipe tanks finally.

CO2 seems to be a big issue with GDA also, turning the CO2 off for a day or two after you clean a tank might help. I did that and it appeared to work.
I'm a long way from being sure about this, but I always start off this way and go from there as I rule out one by one. At least I can grow it finally.

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

I know your feelings about leaving it alone.
That is typically counter to what I know as well, that's why the two tanks surprised me.

Critters, or a good scrub + water change, then no nutrients for 1-2 days might be another way. If I let the CO2 taper off, I seem to get a re emergence, but if I turn the CO2 off entirely after a scrub, then it has not come back.

I need to do this a few more times and it will not hurt to try these methods as I go through them either. the worst will be you are back where you where anyhow, the best: you figure out a way to beat it and then share it with everyone that is suffering.

I know chemical means are not required.
I tend to try those only if everything else has not worked and I have not seem evidence that it'll be useful here or would come to that point.

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Let it go another few days.
Turn light off for a day and then clean good + large water change and do not add any ferts for 1-2 days.

See what that does.

GD does not harm plants, like GW, so you can afford to play around with it and see what affects it. Gw was a nice model since it alos had that quality but I also found out how to induce it easily. I am not yet there with GDA, I do not know why it appears and disappears yet.

I know how to get rid of it generally for myself.........but it needs to be consistent to be useful to everyone.

I'm down to only one tank that has any left

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Yes, see what happens.

I'm not certain it'll work, the next step would be turning off the CO2 for 1-2 days. You do not want to do that for more than 1-2 days ever though unless if combined with a blackout.

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Well, my last tank is dying off just as I'd predicted if I left it alone.

There's some hardned green dust, it's sort of different, not so soft, has muscilage, spotty pattern.

This seems to be the end of the cycle for the vegetative growth.

If I attacked the GDA and cleaned and wiped it off, then it would and did get worse. GDA will also form a nasty green film slime on the water's surface when really juicy.

This neglect method took about 2 weeks total.

Some things that might help:

Turn CO2 off for 1-2 days, maybe lights also.
Do not do water changes etc
Do not scrub it off
If you do a water change, don't add nutrients back, (traces are okay).

Wait 2-3 days, then add them.

The no CO2, the no ferts etc are done only for a 1-2 day peroid really, plants are fine for that long and no algae will come along.

Substrates:
I've seen this same thing occur with Flourite.
I thought it might be the Amano shrimp I added and I got tried of scrubbing the tank. Looks like it was just letting the algae go.

Every single tank I've had has done this same process with GDA.
Same pattern and control results.

This is 7 tanks that all did the same thing.
2-3 times might be luck.

I'm still unsure of it.

ADA substrate is what I now use, but this patterned occured back in 2002 when I was doing this with GDA in hard water also.

My tank water is RO/Tap mix to KH=2.

I tend to doubt that hardness plays much role, nor substrate.
I still don't quite know what triggers a bloom.

That is the key for me.

Regards,
Tom Barr

 

Re: Green dust algae and herbivores

Well, there is a defintiely turning point for this alga.

That much is clear to me after doing this 7-8 times now.
It has nothing to do with me scrubbing either.

Perhaps a mild case can be scrubbed off and harassed to death.

But when the alga begins to form patchy thicken films, and only very light films eslewhere, that's when it's completed it's cycle and is the time to attack.

At this stage, the alga will not swim and reattach to the glass and you can remove it all.

This seems to take a week or two, I also tried added some floating cuttings to block the light. This also seemed to help a little.

But even under full 6w/gal lighting, the alga went through all the stages and only formed something like a soft green spot alga type of film.

By attacking this alga, we never allow it to go all the way to the less resistant (to control) life stages.

Once it does, then we can go in and do a nice water change, scrub etc and then no longer have it come back.

This is the pattern I've seen 7-8 times now.

I've thought it might be simply getting the plants/roots growing good and getting the tank's growth rate up.

Regards,
Tom Barr