Algal Blooms

[Waterbug]

There may be a simplish reason why green water can swing to clear water with blanketweed blooms, then blanketweed usually collapses when the ratio of aquatic plants gets to a tipping point where the uptake fertility is 'locked up' by the aquatic plants, on a well planted pond fertile water can be depleted of fertility in a couple of weeks and go from eutrpophic (fertile) to oligotrphic conditions (http://en.wikipedia.org/wiki/Oligotrophic)

That is the definition of oligotrphic but pond would never approach such level. Maybe if filled with distilled water and then only for a short time as dust blew in. A well planted pond by definition of being "well planted" would always be eutrpophic. It can't be anything else.

 

[adavisus]

Sure, a well planted pond becomes oligotrophic, when heavily planted it can exhaust a pond of trace minerals, fertility in a couple of weeks of a water change.

Voila, clear as a bell. Like a mountain stream.

Regards, andy
http://i93.photobucket.com/albums/l42/adavisus/
http://swglist.wordpress.com/

 

[Waterbug]

Waterbug, I had just read a post of yours regarding going from pea soup to string algae, and how often that happens. So I knew you had a theory of why. I was actually going to pm you to pick your brain. So I'm really glad you posted here, but for the life of me I don't understand what you're saying. I'm sorry, but I guess you're talking above my head.

The links and references do the actual explaining better than I can. CliffsNotes is about as close as I can do.

Are you saying that string algae has some component (allelochemical) that kills the suspended (pea soup) algae? Because I did not notice much, if any, string algae during or after the pea soup stage.

That seems to be common. It's a chicken and the egg deal.

Green water inhibits string algae. Normally green ponds are reported to not have string algae. But there are also a fair number of cases of sort of green water and some string algae...but neither doing very well.

There are many species of algae. We definitely don't understand how string algae over comes the suspended algae because it is also probably producing allelochemicals in addition to resource competition (first in line for nutrients and shading the string algae). In my experiments I had great difficulty growing both suspended algae and string algae in the presence of the other.

One thing I'm sure of is that it takes a surprising small amount of string algae to kill the suspended algae. I cleared small ponds, like 500-800 gal with just a handful of string algae.

String algae grows a cell at a time of course. So to start out with it's rarely noticed. In order to grow it has to eliminate the green water algae. So for allelochemicals to be a factor the string algae must be able to get a toe hold and start producing enough allelochemicals to put the hurt on green water algae. So by the time most people see string algae the war is already over. Couple weeks later the string algae has grown so much people get concerned and report that problem.

Streams and waterfalls seem to give the string algae an upper hand, probably the increased light, but O2 and CO2 could be a factor. Most persistently green ponds I see, green for more than a year, don't have a stream and maybe just a small waterfall.

Interestingly about 15-20 years ago Trickle Towers started to get popular with Koi ponds. These were just for bio filtering, not algae related. Well people started reporting their pond cleared. This may be were Norm Meck got his theory that clear water was caused by bacteria. Everyone was totally focused on bacteria. No one suspected the string algae covering the Trickle Towers were responsible. I sure didn't think about it at the time.

I will do some more reading about allelochemicals and see if I can get a clearer understanding. Thanks. I always love getting more understanding.

Maybe considering allelochemicals you already know about would help.

Poison Ivy produces an allelochemical to try and stop animals from eating it...happens to give most humans a bad rash.

Heard about the leaves and stems of tomato plants being toxic? Allelochemicals. At the same time it produces a fruit to get animals to eat it. Very targeted.

Flowers produce chemicals to attract pollinators. Not an allelochemical but basically the same deal...producing chemicals to get a result.

Maybe you've heard of grass not growing under a walnut tree. I've heard many people from the time I was growing up say the tree "sucked all the nutrients out of the ground" or the "shade killed the grass". People would prune the crap out of their trees to get the grass to grow but all it did was kill the tree...and then grass did grow. The trees produce an allelochemical to reduce growth of other plants from growing in its root zone. No doubt shade helps the cause, but it's the allelochemical that really does most of the work.

Tons of examples of plants producing chemicals for some pretty wild reasons. And allelochemical production to kill other algae has been found in many algae species. Unfortunately not all species have been studied. But to me, to think algae in a pond wouldn't do this, seems the far out theory. And everything else fits too so I'm sold.

 

[joesandy1822]

Waterbug, so I would not want to remove too much of the string algae, or I could be setting up another cycle of pea soup?

JohnHuff, I hope you are right about it being just unsightly. I really hope it doesn't choke out my hornwort, because I really like my little "forest". So do the fish.

 

[Waterbug]

Waterbug, so I would not want to remove too much of the string algae, or I could be setting up another cycle of pea soup?

You could remove all the string algae that you could possibly see and there would still be enough remaining to to produce enough allelochemicals to keep water clear. When the pond initially cleared there was so little string algae that you didn't even notice it.

You could also add fertilizer or sun lamps and green water algae still couldn't grow.

Once string algae has the upper hand it's actually pretty difficult for the green water algae to come back. Using chemicals to kill all algae for a while might do it. You'll see that pattern repeated in many ponds, once clear they stay clear, at least of pea soup green algae.

 

[joesandy1822]

Waterbug, if this is true, and had I known it, I would have deliberately gone to a pond with string algae and taken some to put in my pond. I'm not trying to be a butt, and I mean no disrespect, but wouldn't this be a simple and effective cure to anybody with pea soup? Who wouldn't rather have some string algae than ugly, green water? Why don't people run out and grab some? And why was it not recommended here about a month ago? I could have had 4 or 5 weeks of clear water rather than not being able to see my fish. I'm just asking because I'm sure it will come up over and over again on this forum somewhere. And that seems like a pretty darn simple cure.

Thanks!

 

[crsublette]

Are you saying that string algae has some component (allelochemical) that kills the suspended (pea soup) algae? Because I did not notice much, if any, string algae during or after the pea soup stage. I will do some more reading about allelochemicals and see if I can get a clearer understanding. Thanks. I always love getting more understanding.

In my first post (post#2), 5th paragraph, there's a hyperlink to a good article, with actual references, that will give ya a good explanation and further reading to do about allelopathic chemicals.

 

[crsublette]

... There are also a fair number of cases of sort of green water and some string algae...but neither doing very well.

There are many species of algae. We definitely don't understand how string algae over comes the suspended algae because it is also probably producing allelochemicals in addition to resource competition (first in line for nutrients and shading the string algae). In my experiments I had great difficulty growing both suspended algae and string algae in the presence of the other.

One thing I'm sure of is that it takes a surprising small amount of string algae to kill the suspended algae. I cleared small ponds, like 500-800 gal with just a handful of string algae.

Waterbug, if this is true, and had I known it, I would have deliberately gone to a pond with string algae and taken some to put in my pond. I'm not trying to be a butt, and I mean no disrespect, but wouldn't this be a simple and effective cure to anybody with pea soup? Who wouldn't rather have some string algae than ugly, green water? Why don't people run out and grab some? And why was it not recommended here about a month ago? I could have had 4 or 5 weeks of clear water rather than not being able to see my fish. I'm just asking because I'm sure it will come up over and over again on this forum somewhere. And that seems like a pretty darn simple cure.

Thanks!

BINGO!!

Joesandy, yep, you are correct in your motivations to ask those questions. If it were primarily the macroalgae, then we would be actually seeing viable macroalgae products being sold in retail stores, much like pond plants, as "THE" organic method for big freshwater ponds to remedy pea green water algae rather than using UV devices. There would absolutely be a market for this due to some folk's dislike of UV devices, especially in the aquaponic hobby.

With all of the research into bacteria to jump start bio-filtration, then the assumption would be entirely reasonable to say there would be an organization that is just as adamanent in their research of macroalgae for freshwater ponds to combat pea green water algae and water pollution, where absolutely there are macroalgaes grown in freshwater eutrophic environments to clean water.

There are actually hundreds of organic products with terrible efficacy to the point of some being flat out scams. There are even pond store retailers relabeling oat straw to be sold as the miracle product of "barley straw to combat algae". So, if there was even a small chance of even an amateur keeping and selling viable macroalgae, then it most definitely would have been done already. Even if it were a scam like many pond retail store products, then they would still do it.

However, the "macroalgae to remove pea green algae" product likely has such of a terribly low efficacy, or even at times zero chance of successful, that even pond stores or shady pond merchants would not sell as a product for such purposes.

The profit margin on such of a product would be huge due to how easy it is to culture macroalgae once it starts to grow.


Also, absolutely there are hobby goldfish ponds out in the world with string algae and the green pea water algae still coexisting in the same water; even if they are not thriving, they are still alive and coexisting in the same water.


So, I think there is much more to the "combating algae" story and the allelopathic chemical is just one of the important chapters in the book along with the many other important chapters.

 

[crsublette]

Another tidbit here.... Coral reef hobbyists do not use macroalgae scrubbers to control the floating pea green water algae. These hobbyists use the macroalgae for nutrient management, since coral reef are incredibly sensitive to being harmed by the smallest abundance of particular nutrients and the algae in the tanks actually have a symbiotic relationship with the coral reef and other microorganisms. In planted aquariums, particular species of macroalgae are used to deter the more harmful macroalgaes algaes that can suffocate the plants, but still they have to do proper maintenance by trimming the leaves that show signs of the more harmful macroalgaes.

Is there a macroalgae that can combat the floating pea green water algae? Sure. Is it as simple as saying "string algae is what kills floating pea green water algae"? Nope. So, then... What allelopathic chemical is present that is killing string algae whenever it actually does collapse if it is not Liebig's law of minimum ?? I guess all there is left is an allelopathic chemical created by bacteria killing the string algae. So, when the string algae is gone, then floating pea green water algae should appear. Correct? Nope. Sure, in terrestrial biology, allelopathic chemicals are very well understood. Although, it is a completely different matter when the context involves aquatic biology.

Again, I reiterate my first sentence in post#2.... "Honestly, I don't think anybody knows beyond theories and gossip and I think this is why it can be a heated discussion, that is since nobody, including me, really knows much of anything to pinpoint an easy answer that works in our context of an outdoor pond."

 

[Mucky_Waters]

Waterbug, if this is true, and had I known it, I would have deliberately gone to a pond with string algae and taken some to put in my pond. I'm not trying to be a butt, and I mean no disrespect, but wouldn't this be a simple and effective cure to anybody with pea soup? Who wouldn't rather have some string algae than ugly, green water? Why don't people run out and grab some? And why was it not recommended here about a month ago? I could have had 4 or 5 weeks of clear water rather than not being able to see my fish. I'm just asking because I'm sure it will come up over and over again on this forum somewhere. And that seems like a pretty darn simple cure.

Thanks!

Actually string algae is much harder to control and eradicate than green water algae. I've seen string algae so bad in ponds that the fish have trouble swimming around, and manual harvesting of the stuff from ponds can be a tedious task that never ends, and don't get me started on how quickly it can plug up filter systems and screens.
Green water on the other hand, is simple to eradicate. Simple hook up a properly sized UV light and sit back and wait a few days. Problem solved.

 

[JohnHuff]

Our ponds are a living system just like people. No two can be exactly alike and after 10 years, I'm still learning about mine. Once in a while I'll have different ideas, try them out on the pond and bounce ideas on the forum. What works now might not work next year. But learning and trying different things out is part of this hobby (or any other) and half the fun. This season is coming to a close but I'm already looking forward to next season and what to do!

"Honestly, I don't think anybody knows beyond theories and gossip and I think this is why it can be a heated discussion, that is since nobody, including me, really knows much of anything to pinpoint an easy answer that works in our context of an outdoor pond."

 

[Waterbug]

Waterbug, if this is true, and had I known it, I would have deliberately gone to a pond with string algae and taken some to put in my pond. I'm not trying to be a butt, and I mean no disrespect, but wouldn't this be a simple and effective cure to anybody with pea soup? Who wouldn't rather have some string algae than ugly, green water? Why don't people run out and grab some? And why was it not recommended here about a month ago? I could have had 4 or 5 weeks of clear water rather than not being able to see my fish. I'm just asking because I'm sure it will come up over and over again on this forum somewhere. And that seems like a pretty darn simple cure.

I thought the same thing. As I posted earlier when I first saw this I did a fair amount of work on creating a filter just to grow string algae...I could smell nobel peace prize. Like I said earlier, in many cases the string algae died and the green water lived. Makes me think the single algae has some chemical defenses of its own, in addition to resource competition I assume, because it's so common in the plant world.

My work with algae doesn't have any good data. Proving a plant has an allelochemical isn't too easy. There are a few, and I mean a few, aquarists doing current and serious work on this topic using refugium tanks. I assume there are other plants with the same ability since green water algae would be a big problem to any underwater plant. I assume don't know if every species has the ability. I assume it's many of them since ponds suddenly clearing is so common.

I think stores are selling this cure and have been for years. When you buy a pond plant you're virtually always also buying string algae too. A marginal plant is going to be set just under the water surface, conditions string algae might need to survive the single cell algae. Streams and Trickle Towers have this same effect, being able to grow string algae in green ponds when none was present before. Could be increase sunlight, could be a gas thing O2, CO2, or something else entirely. Still possible Norm Meck's theory is correct and the toxic substance in water is produced by bacteria. Hard to prove.

20 years ago in ponds this would have been a big deal. UV filters were expensive. Green water was a serious problem. Today UV is cheap 100% guarantee. String algae can be difficult to grow. These are living systems and will never be 100% reliable like UV. Aquariums are another matter. They have valid reasons not to want UV so a fix to green water without UV is going to be a huge deal.

Just like with ponds and everything else whenever there is a new idea there will be line of people around the block to say the world is flat. Don't get me wrong...I think it's a good thing. People shouldn't just believe stuff because they read it some place. Virtually everything we have in ponds was treated the same way. Would be nice is people were a little open minded and actually tried a few simple experiments like testing nutrient levels in green and clear ponds if they don't want to believe all the available data. That's pretty simple and easy.

So the few aquarists open minded enough to test the allelochemical theory using refugium tanks are really getting hammered in aquarium forums. Name calling, the works. Forum SOP. But these aquarists doing the work are still plugging away. I don't think they'll ever be able to "prove" allelochemicals but they're slowly eliminating other causes for killing single cell algae. Really slow because they're running into the same thing I did...learning how to get single cell and macro cell algae to grow for tests. It's expensive and slow. But they'll get there I think.

However, even if they prove the allelochemical theory tomorrow I'll bet 20 years from now people will still be repeating the same old myths in pond forums. Just a guess based on the past 20 years.

If you want some kind of heavy reading about this you could take a look as Diana Walstad's book ECOLOGY of the PLANTED AQUARIUM - A Practical Manual and Scientific Treatise for the Home Aquarist. Although it's about aquariums and it's a whole deal, she does as good a job of covering allelochemicals and algae too. The book is kind of the one thing that keep the refugium testers going. The book has been out awhile so you should be able to find it at the library.

You can also Google "allelochemical refugium" and probably find the current work being done.

But purely for learning. Today, in ponds, UV is the fix.

 

[crsublette]

I think stores are selling this cure and have been for years. When you buy a pond plant you're virtually always also buying string algae too. A marginal plant is going to be set just under the water surface, conditions string algae might need to survive the single cell algae. Streams and Trickle Towers have this same effect, being able to grow string algae in green ponds when none was present before. Could be increase sunlight, could be a gas thing O2, CO2, or something else entirely. Still possible Norm Meck's theory is correct and the toxic substance in water is produced by bacteria. Hard to prove.

To my self, I predicted exactly the same response. Yet, there are still ponds with trouble pea green water even after their pond plants introduced in the pond. Actually, I would bet cash money that most ponds having trouble with pea green water algae actually have already bought and introduced pond plants from a store.

Sure, Norm Meck's theory is possible, but too many folk are taking this possilibity to indicate it is the only reasonable explanation, even with the poor efficacy of the possibility.

 

[crsublette]

20 years ago in ponds this would have been a big deal. UV filters were expensive. Green water was a serious problem. Today UV is cheap 100% guarantee. String algae can be difficult to grow. These are living systems and will never be 100% reliable like UV. Aquariums are another matter. They have valid reasons not to want UV so a fix to green water without UV is going to be a huge deal.

Since string algae is so difficult to grow, then why is it so easy for it to grow, almost instantly, in streams, on waterfalls, and by aquaculture folk fertilizing their fish farms ??

 

[crsublette]

Just like with ponds and everything else whenever there is a new idea there will be line of people around the block to say the world is flat. Don't get me wrong...I think it's a good thing. People shouldn't just believe stuff because they read it some place.

I completely agree!!