My take on green water

[Bluerooster]

I'm still relatively new to this pond thing. And as such I've been learning a lot. When I put my pond in, it was simply to do something with a sinkhole at the barn.
It kinda snowballed from there. Its about 3000 gallons total, with two ponds, stream, and two "falls". First year, I fought green water, tooth and nail, with all kinds of additives, thinking I was doing good. One of the additives was bacteria. But I had to feed the bacteria something, so I bought a dozen minnows at the local bait shop.

The minnows didn't survive long. Well, one did. anyway, I continued to fight green water, striving for crystal clarity. I fabricated filters, bought filters, put in plants, added more chemicals, water changes, etc. All of which made more work for me, but did nothing for the pond. This year, starting my 4th year in, I just decided to let it go. I sed "ta heck with it". When all the fish are gone, I'll fill it in, and plant grass.

Well, I do skim the debris from the surface with a net from time to time, and empty the skimmer basket, but that's about it. Guess what! Now that I've just left it to it's own devices, the water is reasonably clear, the plants are growing, the string algae is thriving, and the fish are loving it. There is all kinds of aquatic life that has materialized seemingly from thin air. Salamanders, frogs, snails, etc.

Water quality was never an issue, just thick pea soup. Which I unwittingly encouraged with all the additives over the years. So my take on this is; when you get your pond in, and running, just leave it alone for a while, and see what happens. Sometimes it's a day or two, or mabe even a month or more. But once it reaches it's balance, it will do what normally happens in nature. And isn't that what we want is for our man-made ponds to appear to be a natural water feature, and not a swimming pool?

Once in a while there will be an algae bloom, but it clears up on it's own in not over a week or so. I just let it go.

Oh BTW the first bloom of the season

 

[cas]

Yep. It's hard to do, but the best thing to do is to let the pond take care of itself.

 

[mgmine]

My thought on ponds is pretty much the same. A little knowledge can be dangerous. You test the water, read about what you think you found on the internet and then start fixing the problem. That's when the troubles begin. Buy this and that then some more and repeat. Change the filter, change the media, add some natural stuff then add some chemicals then wait for a few months or maybe years and sooner or later the green water will be gone. In the meantime, your pond looks like a green cesspool. I went through the same cycle until I got fed up with waiting. Summer is too short and I wanted instant gratification, or at least within a few months. My solution which I mention all the time was a simple UV light. I turn it on when I open the pond and within a week my pond is clear. That's my maintenance program. Then I feed the fish or don't feed them, They're carp and carp live on anything including the string algae that grows in the pond. I leave that stuff alone and only bring out the big guns when it gets in the waterfall and stream. Since I don't allow my fish to read while they are in their school they don't know what the internet says and since they don't know what is good or bad for them they do just fine. So why worry? There are only two things to worry about, either you're sick or you are well. If you are well there is nothing to worry about but if you're sick there are two things to worry about, either you'll live or you will die. If you live then there is nothing to worry about but if you die there are two things to worry about, either you'll go to heaven or hell. If you go to heaven there is nothing to worry about but if you go to hell you'll be so busy shaking hands with old friends you won't have time to worry.

 

[CometKeith]

I'm still relatively new to this pond thing. And as such I've been learning a lot. When I put my pond in, it was simply to do something with a sinkhole at the barn.
It kinda snowballed from there. Its about 3000 gallons total, with two ponds, stream, and two "falls". First year, I fought green water, tooth and nail, with all kinds of additives, thinking I was doing good. One of the additives was bacteria. But I had to feed the bacteria something, so I bought a dozen minnows at the local bait shop.

The minnows didn't survive long. Well, one did. anyway, I continued to fight green water, striving for crystal clarity. I fabricated filters, bought filters, put in plants, added more chemicals, water changes, etc. All of which made more work for me, but did nothing for the pond. This year, starting my 4th year in, I just decided to let it go. I sed "ta heck with it". When all the fish are gone, I'll fill it in, and plant grass.

Well, I do skim the debris from the surface with a net from time to time, and empty the skimmer basket, but that's about it. Guess what! Now that I've just left it to it's own devices, the water is reasonably clear, the plants are growing, the string algae is thriving, and the fish are loving it. There is all kinds of aquatic life that has materialized seemingly from thin air. Salamanders, frogs, snails, etc.

Water quality was never an issue, just thick pea soup. Which I unwittingly encouraged with all the additives over the years. So my take on this is; when you get your pond in, and running, just leave it alone for a while, and see what happens. Sometimes it's a day or two, or mabe even a month or more. But once it reaches it's balance, it will do what normally happens in nature. And isn't that what we want is for our man-made ponds to appear to be a natural water feature, and not a swimming pool?

Once in a while there will be an algae bloom, but it clears up on it's own in not over a week or so. I just let it go.

Oh BTW the first bloom of the season View attachment 120820

Exactly! This what we tell all the new members of GPF. Leave it alone and let the nitrogen cycle do it's thing and don't use any chemicals except for declor... but everyone wants instant gratification and they can't bear to show off their new pond to family and friends that is an icky pea soup color! Other mantras for a successful pond: don't over populate or overfeed, but those are stories for another day!

 

[Waterbug]

Whenever I read this type of post I say to myself "wait for it...string algae" and am never disappointed. Normally it goes like this: long battle with green water, finally it suddenly clears. Then the person says "now I have a string algae problem".

Not that this matter or anyone really cares but just for fun here's some history from very long ago...

Norm Meck wrote an article (I can't even find a link to it any more) about green and clear water. He did an experiment where he mixed water from a green pond and a clear pond in different ratios. Very quickly the water from the clear pond killed the algae from the green pond. And it happened at different levels, 75% clear water killed more algae than 25% clear. This experiment is very easy to reproduce, just has to be clear water from a pond where the water had been green previously at some point.

Norm stated a theory, a guess, at what was in the clear water that would kill green algae almost on contact. His theory was heterotroph bacteria produced the chemical in clear water so it would destroy the cell wall of algae so it could digest the inside. Kind of not a great theory imo but in those days bacteria was really the only thing anyone knew about so it was kind of a catch all for explaining any mystery. It seems unlikely that a creature would evolve a chemical that eliminated it's food supply. Possible. Very difficult to prove.

One day I was dealing with some aquatic plant beds that had a lot of string algae. I threw a big clump of string algae into another pond that was green, not sure why I did it, just screwing around maybe. Next day that green pond was crystal clear. You hear that a lot, clear water appears almost over night and it is shockingly clear. I ended up doing some experiments and mostly found I had a very hard time growing both string algae and green water algae in order to do the experiments. I had to be meticulous in keeping the two in separate water containers or they didn't grow. I could never find definitive proof (in the online world is there even such a thing?) but enough to prove to myself that string algae was producing the chemical. The green water algae was also producing chemicals to kill string algae in addition to its main weapon of shading out string algae.

There were some signs in the ponding world that string algae was causing clear water, but it's the last thing most ponders wanted to see. String algae is the enemy after all. There was a very well respected ponder, the guy who invented the pipe boot (Greg somebody?), who had 2 green ponds and built a shallow stream between the two. His 2 ponds cleared shortly afterward. People speculated why. He then started talking about his new problem, string algae that started in the stream.

And there was a pretty famous filter called a Trickle Tower which was a pile of rocks above the water over which pumped water flowed. The idea was this was a bio filter, a precursor to Bakki shower filters. These were built to handle ammonia. But there was a side effect, green ponds cleared. Obviously it must be bacteria clearing the pond since bacteria was why they were built. The only problem with Trickle Towers was that they became covered in string algae.

This all happened more than a decade ago, even before UV filters were widely available. Back then green water was a huge problem for pond keepers. Now it's simple, add a UV filter. So we really don't care much any more about why green water becomes clear.

During the last decade a few scientists have been doing more work on how plants compete against each other. The production of allelochemicals is one such defense. There is a great documentary What Plants Talk About by Nature that talks about it although it does keep discounting how widespread this even though the more scientist look the more they find. One quote that is true and funny is the scientist saying "If you talk to a layperson about plant behavior they'll think you're crazy. If you talk to a scientist about plant behavior they'll think you're crazy and wrong."

In both cases the structures reduced the green water algae's main defense against string algae, shade. Most water gardens and koi ponds have pretty straight sides and green water algae establishes quickly in new ponds. That gives string algae few places to get established. Trickle Towers, streams, waterfalls can give string algae a place in the sun.

That all is kind of weird because there had been published and accepted studies on marine algae in which allelochemicals played a big part. For some reason scientists, and people in general, seem to be always been much more interested in the marine environment than freshwater. It seems like we take for granted we understand the world around us, even through that keeps turning out to not be very true. That marine algae used allelochemicals never seemed to trigger any notion that freshwater algae did too. Weird.

More directly a few aquarists started to see a connection between clear water and string algae. They built separate tanks to grow string algae and ran tank water thru that. They have a name for it which I forget. Aquarists are a pretty serious bunch, really into these kinds of things. And there was a pretty well known aquarist book (I forget the title) which had a chapter on plants and allelochemicals. But still a lot of aquarists in forums thought it "crazy". Super easy for them to do the experiment for themselves, but even easier to just dismiss it. And besides, they had a history, decades, of publicly saying as experts that there were other reasons for clear water. Most "facts" were about starving algae of nutrients or light all of which were extremely easy to disprove should anyone had cared.

Those were the days. So much to learn, so interesting. Now it's super easy, plug in a UV filter. I kind of miss those old days. Every other month someone had a new type of filter, a new theory.

Today there is still a very important reason to hold on to the old ideas. You can't sell string algae. I mean you could, but few would buy it. What you can sell is bacteria in a bottle, barley straw, magnets, and other snake oil cures. And of course many online experts have their reputation to think about too.

 

[Lisak1]

Nice to see you @Waterbug - you always give me lots to think about.

 

[MajorDan]

So I am just waiting for the string algae to get a toe hold in my waterfall and until then I am enjoying the fish playing hide and seek in the deep dark green water. Nature makes the pond amusing and fun and a great hobby.

 

[addy1]

I filter with plants, lots of plants and pea gravel. Never have a issue with string algae or green water in the ponds with fish. The waterfalls I have never get string on them. And my ponds are full sun.

The slow moving, i.e. very low water flow, fishless ponds get a bit of string in the spring which goes away. Right now one of the small ponds is covered with parrots feather, no string, the lotus tub has string, but the lotus are just starting to grow. It will be gone in a few weeks.