Getting rid of Epistylis

[cuatromil]

Hello.

Long time reader, first time poster.

I have a 15 gallon coldwater tank that I am trying to convert to a river tank. I have a powerhead that gives me 200 gal/hr, a fern from Tropica, an amazon swordplant, a foxtail plant, and other common plants.

Substrate is a layer of sand+clay covered with smooth gravel and lots of medium to large smooth stones, plus a pice of driftwood. I have 3 hillstream loaches and 1 bala shark (from a previous tank).

Ammonia is non detectable, I don't have a nitrate kit or hardness kit, and the temp. is 26C.

The walls of the tank were covered with what I tought was brown algae, and I had some snails taking care of it, but the snails were also eating the green algae growing on the rocks, so I took them out.

The green algae is habitat to all the microorganisms that the hillstream loaches feed on, so some green algae is OK on this tank.

The problem is that what I tought was brown algae is takin over all plant and rock surfaces, and seems to be outcompeting the green algae.

I took a sample to the microscope, and it is Epistylis (looks like Vorticella, but the stalks don't contract, and grows in multi branched, plant like colonies). I have yet to make a skin scrape to see if the fish are infected (epistylis causes red sore disease).

I don't want to nuke the tank with copper right now, since it took me quite some time to establish the green alga and all the protozoa living there (I have lots of rotifers, ciliates and small crustaceans).

So here comes the very difficult question: Does anyone know of a way to get rid of vorticella without killing all the other microorganisms living there?

Meanwhile, I am starting a new green algae culture outside the tank, and will reintroduce the snails.

Thank you very much.

 

[OrionGirl]

http://www.koiimporters.com/epistyli.htm Not sure how helpful this is, as I suspect that a salt concentration high enough to kill this will also damage some of the other micro fauna. Maybe take a sample out of the tank and test it to see? It does look like there are some speciesof epistylis that are not parasitic.

 

[cuatromil]

Thanks

Thanks for your reply. I will try salt in a small sample.

 

[Tom.E]

Grazing snails will incidentally ingest stalked protozoans, so adding them back to the tank is a good idea. The concentrations of salt you’ll need to eradicate the Vorticellans and Epistylis will probably also damage the meiofauna community in the tank.

I am curious how you established and maintain the protozoan population. Population blooms of large stalked protozoans like Epistylis or Vorticella requires a decent density of picoplankton in the tank. Adding pond water or cultured water to the tank could be part of the problem.

A protozoan/NaCl study you may be interested in reading http://www.nencki.gov.pl/pdf/ap/ap574.pdf




Tom

 

[cuatromil]

Thank you Tom for your link and reply.

Answering your question, I tried to start some kind of live food culture for my molly fry, got a lettuce leaf from an organic farmer's market, and put it drinking water in a small jar with a few drops of liquid fertilizer. A few days later I had green water and daphnia, as well as lots of unidentified microorganisms. I divided this initial culture in several other highly diluted jars, so now I have over a dozen jars, all with a different kind of predominant organism.

I put rocks in the greenwater jar that has mostly daphnia and algae until they become algae covered, and then put the rock back in the hillstream loache's tank until they suck them clean.

The interesting thing is that the greenwater tanks have only daphnia, lots of free swiming protozoa, some kinds of flat worms and round worms, but no stalked organism that I can find.

The Epystilis seems to have upset the balance in the main, and is outcompeting everything, it looks bad, and I read that it can parasite fish. I would like to find out a way to favour other microorganisms over the Epystilis. (In mushroom culture I am used to helping yeasts on some stages, bacteria on others, and fungus at the end).

I know have a critters only tank, no fish, left uncovered, where i have lots of microorganisms, as well as naked eye visible algae, planaria, roundworms, insect larvae, and exotic aquatic plants. This is becoming my favorite tank.