Home |
Search |
Today's Posts |
#7
|
|||
|
|||
Floating Clumps of Flourescent Green Algae
ajames54 wrote:
There have been a couple of posts lately about algae described like this. Or describing algae that forms in lumps that break up and dissolve on contact. Or describing algae the has a really disgusting smell ... Any of these posts could in fact be describing cyanobacteria, also known as Blue-Green Algae. Cyanobacteria, as the name says, is more accurately a bacteria than an algae. Though it certainly appears like algae it is best to think of it as bacteria that has developed the ability to produce its own food through photosynthesis. Some, though by no means all are actually toxic, currently the is a bit of a crisis on the California coast, hundreds of seals and otters are sick after eating fish and shellfish poisoned by this stuff. Some species of bluegreen algae (and other algal groups) produce toxins that are harmful to aquatic wildlife and even humans. The vast majortiy do not. Most that do are marine, not freshwater species. This means that those most commonly found in backyard ponds are not going to cause this problem: your koi and goldfish are exceptionally unlikely to die from such toxins. Dissolved oxygen and pH shifts are the real danger. Because of its unique abilities it is extremely difficult to deal with, most traditional methods of algae control simply don't work. Tinting the water and increasing shade is ineffective, because it can move about and adjust its buoyancy (one of the reasons it often floats up overnight) it will simply migrate to the areas where there is light. It is very tolerant of differing water conditions and can survive in conditions that would kill fish or other plants, (it was one of the first organisms to appear on earth, when the planet was still inhospitable to most life). Like other animals it is able to store the nutrients it needs when there is a surplus (Many of the "nitrogen fixing bacteria" you want in your soil are cyanobacteria) so massive, frequent water changes may help but will not eliminate the problem. Again, this is true for some bluegreen algae, but not all. Most species that become problematic in backyard ponds are susceptible to the same control techniques applied when managing green algae. There are exceptions. The best way to proceed after removing excess decaying material from the bottom of the pond is to combine physical removal of the Cyanobacteria while encouraging the growth of higher plants. pulls out soapbox. It's the nutrients. Manage the nutrients (this includes the above mentioned methods in combination with others) and the algae will not be a problem. Cyanobacteria is uni-cellular (though it often grows in colonies) so it is difficult to mechanically separate it from the water, fortunately those cells are fairly large so a fine filter like quilt batting will work (Though if you put the quilt batting in your bio filter you need to change it regularly and be aware that this may damage the "good bacteria" that are colonizing your filter.) You should also gently skim clumps off the surface with something like an old nylon stocking (the finer the better). A note: green algae are also unicellular, and exist that way (pea soup), as colonies (pea soup and clumps), or as filaments (string algae), dependent on species. Bluegreen algae, dependent upon species, exists in the same forms. Not all species are filterable. Encourage your existing plants to grow and if necessary add more plants, over time the higher plants will out compete the cyanobacteria for the nutrients in the water... (which is pretty much what has happened over the entire planet and is a good solution to most algae problems). You should also make water changes, but be aware that some water sources contain phosphates (Some sources I've read suggest that Cyanobacteria blooms in high phosphate conditions, primarily because it can store nitrogen compounds) Yeah. I've also heard of people controlling it with small doses of copper sulphate, though this is dangerous as even a small overdose can kill your biofilter, invertebrates, plants and fish. Yeah. Chelated copper compounds are more effective, but the same problem exists: it doesn't take much of a dose change to harm other aquatic denizens. In a small pond or an aquarium it can be effectively controlled with doses of Erythromycin (called Myacin as aquarium medication) double the duration of the treatment from that listed on the package. (This can get Very expensive Very quickly)... Use of antiobiotics in aquaculture is common. However, using such products in a backyard pond can destroy the balance many have attempted to achieve, especially those employing biofilters. Anyway if that was not already too much info you can check out these links http://www.ucmp.berkeley.edu/bacteria/cyanointro.html http://www-cyanosite.bio.purdue.edu/ http://www.hc-sc.gc.ca/ehp/ehd/catal.../iyh/algea.htm |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Non-floating Plants Floating Root | Ponds (moderated) | |||
Floating Plant's Floating roots? | Ponds (moderated) | |||
Cliveas $2 per stem from clumps | Australia | |||
Algae Algae Algae | Freshwater Aquaria Plants | |||
Floating Clumps of Flourescent Green Algae - Lee | Ponds |