Am currently under attack by Green Dust Algae

[jonny_ftm]

You're right (as often, not to say always...) Tom.

I find a low light/high CO2 nano with slow growing plants and tons of snails much easier to maintain than a bigger tank. Exept WC (quick because of low volume) and ferts, it's quiet no maintenance.

Without CO2 it turned into a disaster in my case. Much harder than a bigger tank with no CO2. Had to back up to EI+CO2 despite months of fighting and loosing 80% of the biomass. This is even with an organic soil...

 

[dutchy]

I have dropped Fe levels to 0,25 and it's a little bit better. it's there, but after 3 days no real need to clean. Today I started to add 1 ppm of Mg per day, as in Yohan's case.

Curious what will happen.

Of course I have ro repeat each test, so it will take some time.

 

[Tom Barr]

You're right (as often, not to say always...) Tom.

I find a low light/high CO2 nano with slow growing plants and tons of snails much easier to maintain than a bigger tank. Exept WC (quick because of low volume) and ferts, it's quiet no maintenance.

Without CO2 it turned into a disaster in my case. Much harder than a bigger tank with no CO2. Had to back up to EI+CO2 despite months of fighting and loosing 80% of the biomass. This is even with an organic soil...

Non CO2 nano's are IDEAL.

I'm not sure why many do not see the simplicity.

 

[jonny_ftm]

Non CO2 nano's are IDEAL.

I'm not sure why many do not see the simplicity.

Maybe many problems in my case, like too much daylight, plants more sensitive to CO2, very low light on some parts?
BBA envaded the tank when I stopped CO2 and WC. I tried a slow decrease in CO2, injecting very low doses that won't even change the drop checker color. Stopped WC and kept with a lower dosing routine. After 8 weeks, I had to backup to CO2 + EI

Maybe I should try again once but probably, the choice of plants will be a bit restricted compared to what I do now...

 

[Yo-han]

I have dropped Fe levels to 0,25 and it's a little bit better. it's there, but after 3 days no real need to clean. Today I started to add 1 ppm of Mg per day, as in Yohan's case.

Curious what will happen.

Of course I have ro repeat each test, so it will take some time.

Really hope it will work, but since I daily dose Mg, GDA never returned! Off course it could be due of something else, so I really want to know the outcome, saves you some snake oil as well!

 

[jonny_ftm]

Well, again, these are too fast assumptions. Why do I have Fe from 0.4 to 0.6 and many here report even higher Fe and we don't have GDA?
The very simplistic approaches with PO4 = algae, Fe = algae, Mg = algae... will take you away from the real issues.

One thing is sure though, low CO2 with high light will trigger all kinds of algae

 

[Tom Barr]

Really hope it will work, but since I daily dose Mg, GDA never returned! Off course it could be due of something else, so I really want to know the outcome, saves you some snake oil as well!

Be nice if this is the case.

 

[Tom Barr]

Maybe many problems in my case, like too much daylight, plants more sensitive to CO2, very low light on some parts?
BBA envaded the tank when I stopped CO2 and WC. I tried a slow decrease in CO2, injecting very low doses that won't even change the drop checker color. Stopped WC and kept with a lower dosing routine. After 8 weeks, I had to backup to CO2 + EI

Maybe I should try again once but probably, the choice of plants will be a bit restricted compared to what I do now...

since it's a nano............Excel makes a very economical and simple solution....then you are sort of going the non CO2 route, some algicidal stuff and increased growth, less competition for carbon.

 

[Yo-han]

Well, again, these are too fast assumptions. Why do I have Fe from 0.4 to 0.6 and many here report even higher Fe and we don't have GDA?
The very simplistic approaches with PO4 = algae, Fe = algae, Mg = algae... will take you away from the real issues.

One thing is sure though, low CO2 with high light will trigger all kinds of algae

That is not what I really said! PO4 = algae, Fe = algae, is about EXCESS, I assume a DEFICIENCY of Mg here. Big difference!

Only leaves the question, can you identify the deficiency on the kind of algae you are having. In this case, is a specific Mg deficiency responsible for GDA?

In my case, it was the only change I made. So I suggested it and hopes it works for dutchy as well.

 

[dutchy]

Well, again, these are too fast assumptions. Why do I have Fe from 0.4 to 0.6 and many here report even higher Fe and we don't have GDA?
The very simplistic approaches with PO4 = algae, Fe = algae, Mg = algae... will take you away from the real issues.

One thing is sure though, low CO2 with high light will trigger all kinds of algae

You're missing the point here. In a previous post (which you probably didn't read) I citated a scientific research paper in which was stated that Ankistrodesmus cell multiplication was the highest at 0,5 ppm Fe, and less at levels below or higher than that. I followed this paper, and there seems to be a difference.

The statement you make: "Why do I have Fe from 0.4 to 0.6 and many here report even higher Fe and we don't have GDA?" is not even remotely close to the subject, because it was never mentioned that Fe in any ppm causes GDA.

 

[Tom Barr]

That is not what I really said! PO4 = algae, Fe = algae, is about EXCESS, I assume a DEFICIENCY of Mg here. Big difference!

Only leaves the question, can you identify the deficiency on the kind of algae you are having. In this case, is a specific Mg deficiency responsible for GDA?

In my case, it was the only change I made. So I suggested it and hopes it works for dutchy as well.

Yes for most observations, deficiency in plants leads to algae, not excess.
This would hold well with the general observations/model about plant growth and algae.
I'm not confident Mg is the trick, but it is easy to test after all and fits well with other nutrients.

The first time I saw it, it was in a tank where th etap water was extremely low in Mg.
I had a rough time inducing it in a couple of tanks in hard water regions.
Lasted all of 2-3 weeks.

In softer water, I was able to keep it going much longer.
Also, ADA AS and other organic sediments may act to strip the Mg out of solution, basically softens the GH.

This might explain the differences I had.
Time and testing will tell.

 

[Tom Barr]

You're missing the point here. In a previous post (which you probably didn't read) I citated a scientific research paper in which was stated that Ankistrodesmus cell multiplication was the highest at 0,5 ppm Fe, and less at levels below or higher than that. I followed this paper, and there seems to be a difference.

The statement you make: "Why do I have Fe from 0.4 to 0.6 and many here report even higher Fe and we don't have GDA?" is not even remotely close to the subject, because it was never mentioned that Fe in any ppm causes GDA.

Basically a bell shaped curve with 0.5ppm at the peak.
So if we want to test, we can add lots more, or very little Fe.

 

[Yo-han]

Yes for most observations, deficiency in plants leads to algae, not excess.
This would hold well with the general observations/model about plant growth and algae.
I'm not confident Mg is the trick, but it is easy to test after all and fits well with other nutrients.

The first time I saw it, it was in a tank where th etap water was extremely low in Mg.
I had a rough time inducing it in a couple of tanks in hard water regions.
Lasted all of 2-3 weeks.

In softer water, I was able to keep it going much longer.
Also, ADA AS and other organic sediments may act to strip the Mg out of solution, basically softens the GH.

This might explain the differences I had.
Time and testing will tell.

So although you don't expect Mg to be responsible, you do think it could have something to do with hardness. Than why couldn't it be Mg?

 

[Tom Barr]

So although you don't expect Mg to be responsible, you do think it could have something to do with hardness. Than why couldn't it be Mg?

Could be, but I'd be surprised if so.
I would want to make sure in other words.

If so, then great!

If not, keep looking.

 

[jonny_ftm]

To test it, we'll need someone using pure distilled with GH from only added calcium, no Mg.

Ferts (with no Mg), CO2 and light should be ok, and all this ideally on a cycled tank.

Other issue, is soil, which often contains Mg.

I really find it hard to reproduce such a problem, completely removing Mg, then adding it.

 

[Tom Barr]

You do not need to remove it entirely............just most of it.
Most DI water softeners remove both Ca and Mg. Soil does not leach much, it typically binds it, eg clays etc.

Also, if you have higher Mg, and GDA, it falsifies the idea fairly well if all else is looking good.

Few folks measure Mg specifically, most just measure GH and do not do the break down between Ca/Mg and subtract the Mg for the Ca test.

 

[dutchy]

But GH is a sum of CA and Mg ions, so could be just Ca and almost no Mg? If so it's not possible to break it down into Ca/Mg ppms?

Anyway, I've been adding 1 ppm of Mg daily for the last 4 days, and I have seen improvements in plant growth, development (bigger leaves) and pearling. I use half RO to keep my KH low for the Erios, so I could have had a slight Mg deficiency, since I didn't add it before and tap water just provides 1,5 ppm with the waterchanges.

GDA is still there however, but the period may be too short for a conclusion. I will clean again today, keep adding Mg and see what happens.

The UV is off to not influence the tests I'm doing.

 

[Tom Barr]

No, a Calcium test breaks it down, then you just subtract the total GH to get the Mg.
"so could be just Ca and almost no Mg?'

You bet, since few bother to test for both individual Ca and Mg.
Old PMDD folks tended to dope the PMDD with more Mg, nothing wrong with it.

I think Ed from PPS brought up some good points about Ca and Mg.....but it got lost in his claims and lack of testing his own hypothesis, and most of these same insights came directly from old discussions on the APD and PMDD users anyway, but he brought it up again at least.

My approach is much more poractical and crude perhaps, simply add it and see. What is the effective range? I do not know the bare min ranges as these will change depending on each tank........same can be said for most any nutrients/CO2/light etc......but I do know the upper ranges I have ussed to be 2-4x higheer than Ed suggested and other folks have stuck with at a maximum.
I do not think anyone would need more than say 5-10ppm however.

I add MgSO4 to the trace mix I use, always have from the old days with PMDD. Later, added this to the GH booster but also left a little in my traces.
Nostalgia.

So I'll be interested to see if this works as sugegst with the Mg, good find if so.
GDA is one of the last hold outs that plagues folks, but a cause and cure would be nice to uncover even if the basis is correlation.
It would explain a lot and the variation as one of the pesky things folks just do not look at much.

Wish I have some GDA.

Now.........here's the real test, can you induce GDA by limiting Mg?
This is conformation

You have nothing to fear in doing so if this is the case, since the cure is to simply add the Mg back and clean the tank up and whip it back into shape, but then you know.......

 

[dutchy]

Wish I have some GDA.

I have plenty to send you

Now.........here's the real test, can you induce GDA by limiting Mg?
This is conformation[/B]

If the GDA stays away I will limit Mg. again to see what happens. It will take some time though.

But if it stays away, then what is the cause? The limited amout of Mg or like in many cases....suboptimal plant growth?

 

[Tom Barr]

Hard to say, one might hypothesize both scenarios, and then it would need to be tested somehow, but I'm not sure how to tease apart suboptimal plant growth and Mg limitation and the algae bloom really, I can offer correlations only, and while the response might be, or might not be very strong.........it would still be tough to suggest one reason definitatively.
The same can be said for the rest of the ferts.

One thing we might be able to say however, based on how much Mg is required to limit GDA...........I think it's clear that we are NOT doing that, particularly when we increase the levels and the algae go away, this is true for most all nutrients I'm aware of.

So it really is...........all about the plants, not some subtle ratio or limitation of dosing etc, as is...........often claimed.

When plants do suboptimally.........even mild, but without a reference to compare what suboptimal is.........the aquarist is really guessing in the dark.
That's why when other aquarist try and grow it and fail, we have some where to start looking.

This causes plenty of myths as you can realize from this unknown example.

But........it might not be Mg also, I suspect it is however and it has improved your long standing GDA issue.

Time will tell, if not........well, back to the drawing board.