Algal Blooms

[crsublette]

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.

I follow Tom Barr's forum, as a premium member, quite closely as well and there is very little talk of allelopathic chemistry being the primary purpose of algae scrubbers/refugiums.

Sounds like you read a few of them. They would indeed be interesting reads. Anything archived that you found particularly insightful??

 

[crsublette]

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.

Ecology of the Planted Aquarium, by Diana Walstad.

Yep, I actually have the book. It is extremely interesting and quite thorough in its explanations with tables and plant species chart and how particular plants impact each other's growth. However, Waterbug, the explanations do not quite make your case as well as you think it does. I still thoroughly enjoyed it. She actually makes the case that the aquatic plants them self, rather than macroalgae, emiting the allelopathic chemicals that deter green water algae.

It does have some good explanations, but yet the book absolutely does indicate issues concerning efficacy, which is what I am concerned about and this is what creates a huge gapping hole in the theory in regards to allelopathy being the "answer".

Sure, I bet it is true with particular species, but we are not talking about particular species here. In this thread, we are simply talking about "floating single cell algae" versus "macroalgae" in general, which I think is far too broad.


Actually, when maintaining planted aquariums, there are two approaches avialable for the hobbist: 1) Walstad's "natural" approach; 2) Barr's estimative index approach.

Dr. Tom Barr actually wrote a quite interesting critique of the book. Ugh, let me see if i can find it in my bookmark library, sure I bookmarked it.

 

[crsublette]

Bah, actually, it was mainly in regards to the tank setups. For anyone interested, google "diana walstad and tomm barr".


Folk will actually learn more from that google reference rather than googling "allelochemical refugium".

 

[joesandy1822]

Well, since I am really trying to do this the most "natural" way possible (personal preference), my conclusion is.....it is what it is. I am happy the pea soup is gone. Now I have string algae. I'm sure if/when this disappears, something new will come along. I am just trying to enjoy the ride, and glad for what I am learning along the way. I won't lie and say the pea soup stage was fun, but it's amazing to me that it went away on its own with no help from me. The fish are thriving and reproducing, the lilies are beautiful, the hornwort recovered, the rest of the plants are starting to multiply, and I can't wait to see what happens this fall and winter that will be equally exciting. Plus I have frogs!!!

Everybody has their theories....seems like not a whole lot is written in stone. And everybody has their own way of going about caring for their pond. Some like the natural approach, some like the UV method for pea soup, and some use chemicals. I think one thing we can all agree on is that we all love this hobby......however we go about doing it.

Everybody have a great weekend! :goldfish:

 

[crsublette]

Joesandy, actually, I am glad this is brought up.

I have strongly believed in reading literature in other hobbies to better understand "how things are working".

Since you want to take the natural way, which is quite fine, then look into Walstad's work. Now, in her aquariums, she actually recommends using sludge and other soil mediums so I am not for sure how this would translate into a pond, but it could make a case for keeping your pond plants potted in some type of sand,etc. Everything in other hobbies might not be applicable to our context in a large freshwater pond, but there might be tid bits that could be useful to know and a bit of creativity to implement them into our larger context.

I do warn you though that Walstad's book is definitely not written for beginners.

Worth a peeking into. :claphands:

 

[crsublette]

Ecology of the Planted Aquarium, by Diana Walstad.

Yep, I actually have the book. It is extremely interesting and quite thorough in its explanations with tables and plant species chart and how particular plants impact each other's growth. However, Waterbug, the explanations do not quite make your case as well as you think it does. I still thoroughly enjoyed it. She actually makes the case that the aquatic plants them self, rather than macroalgae, emiting the allelopathic chemicals that deter green water algae.

In Walstad's study, Acorus gramineus (sedges, rush, sweetflage) and Pistia Stratiotes (water lettuce) actually emits asarone chemical that is toxic to particular macroalgaes and also they consume particular nutrients further to deter the macroalgaes growth.

However, the efficacy of asarone impact on macroalgaes is dependent upon the pollutant equilibrium, which gets further offset by water changes. This comes back full circle to what I stated in post#2, which states, "This is one particular argument point of how folk well suggest water changes encourages algae blooms, of various species, due to the dilution of these allelopathic chemicals."

 

[crsublette]

Well, since I am really trying to do this the most "natural" way possible (personal preference), my conclusion is.....it is what it is. I am happy the pea soup is gone. Now I have string algae. I'm sure if/when this disappears, something new will come along. I am just trying to enjoy the ride, and glad for what I am learning along the way. I won't lie and say the pea soup stage was fun, but it's amazing to me that it went away on its own with no help from me. The fish are thriving and reproducing, the lilies are beautiful, the hornwort recovered, the rest of the plants are starting to multiply, and I can't wait to see what happens this fall and winter that will be equally exciting. Plus I have frogs!!!

Everybody has their theories....seems like not a whole lot is written in stone. And everybody has their own way of going about caring for their pond. Some like the natural approach, some like the UV method for pea soup, and some use chemicals. I think one thing we can all agree on is that we all love this hobby......however we go about doing it.

Everybody have a great weekend! :goldfish:

Joesandy, here is an excerpt, from the Walstad book, for you since you have Hornwort.

If you try to grow Water Lettuce or Duckweed in your pond, then Hornwort will "supposedly" create a 70% growth inhibition of Water Lettuce and a 60% growth inhibition of Duckweed, according to tests done by M R Berenbaum. Is this always true? Nope. There are many mitigating variables to take into consideration as well especially the larger environment we are exposed to with our ponds. So, I would view this as a baseline, but I would not be suprised if the Water Lettuce and Duckweed does better than what the study states.

 

[crsublette]

I strongly encourage folk to buy the book.

To add another teaser for ya, addressing the allelopathic debate, from Walstad, Diana Louise (2013-05-15). Ecology of the Planted Aquarium: A Practical Manual and Scientific Treatise (Kindle Locations 1317-1321). Echinodorus Pub. Kindle Edition.

Most plant allelochemicals are only mildly inhibitory, so scientists sometimes have problems proving allelopathy.

Indeed, an allelochemical may inhibit more when combined with other allelochemicals than when tested alone (i.e., the ‘synergistic effect’)

Allelopathy in aquatic plants is not dramatic. It is subtle. However, all aquatic plants continuously produce a large number and variety of defensive compounds that mildly inhibit all organisms. It is likely that these allelochemicals might have subtle and unrecognized effects on the plants, bacteria, algae, and invertebrates in aquatic ecosystems.

Aquatic botanists have observed that lake areas with heavy plant growth often have reduced algal growth. Granted that some of this apparent inhibition may be due to plant competition with algae for light and nutrients. However, plant-produced allelochemicals could cause a portion of the inhibition. Other inhibition may be due to humic substances. Humic substances, which are phenolic compounds, are derived from the decomposition (rather than the synthesis) of plant phenolics.

So again, it's as I said in post#2 stating, "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."

Not writing this to create a contention. Just pointing it out. :cheerful:


It is all different pieces to the same puzzle. Honestly, I do not believe there is any singular control mechanism to controlling algae.

 

[crsublette]

Joesandy, my apologies for getting riled up here, but I find this extremely interesting and I am quite passasionate about what is of interest to me.

Hopefully it shined a little light to give you some guidance.

To address your string algae, trying planting some sedges, rushes, and sweetflag, but, as winter is upon us and usually takes about a month for plants to fully transition, I do not think there is time for this.

Other than this, elbow grease with a toilet brush will be required to take the string algae out. I am afraid any low dose regiment of peroxide will harm your hornwort so I would be cautious about using it.

So, this is something to think about for next season!!

 

[Waterbug]

Well, since I am really trying to do this the most "natural" way possible (personal preference), my conclusion is.....it is what it is. I am happy the pea soup is gone. Now I have string algae. I'm sure if/when this disappears, something new will come along. I am just trying to enjoy the ride, and glad for what I am learning along the way.

Once macro algae is established and a pond is kept relatively clean, non-green water is normally very long lasting, basically forever. I've seen ponds that are never cleaned get into trouble after a few years.

You will likely see several species of string algae and other macro algae come and go, but there always seems to be a couple present. But if course living systems can't be predicted. But I think the odds are in your favor.

Everybody has their theories....seems like not a whole lot is written in stone.

Theories are only the first step to learning. While allelochemicals have been know for a long time people are making new discoveries all the time. Unfortunately I doubt backyard ponds will get much study beyond hobbyists.

And everybody has their own way of going about caring for their pond. Some like the natural approach, some like the UV method for pea soup, and some use chemicals. I think one thing we can all agree on is that we all love this hobby......however we go about doing it.

I use a UV at first so the pond owners wouldn't have to go thru green water which most people really don't like. Once I could see macro algae I could turn off and remove the UV. No reason to run a UV after that. I assume this doesn't work in some ponds, but worked for me.