Cyanobacteria problem...

[HannahJ]

One of my 10 gallon tanks has recently started growing some bright green sheets of growth that I had originally assumed was algae, but which a thorough internet search has seemed to indicate is cyanobacteria. I'm not too sure of the cause of this--the tank only has three bettas in it, and since I feed them a pellet at a time and partial water changes are weekly, it doesn't seem like it should be a pollution issue. I'm not sure of the exact levels in the tank--my mother has my test kit up at her work for her tank there at the moment--but the tank has been established and cycled for nearly a year now.

My question is this--how should I treat this problem besides just vacuuming up as much of the green stuff as possible each change? Most of the sites showing up in searches seem to be for companies pushing a chemical solution, but I would prefer to go organic if at all possible. Will otos or other algae-eating fish tackle the cyanobacteria, even if it isn't a true algae? A plecostamus probably wouldn't be a viable solution, given the size of the tank.

All advice or help is appreciated! Thanks.

[nitrous]

is it the blue green algae, also what are the water perameters, how much light is in the tank and what kind of tank is it

[HannahJ]

I guess it's blue green algae...isn't that just another name for cyanobacteria, or am I mistaken? It's a 10 gallon glass tank with an undergravel filter, and fluorescent lighting that's on maybe 10 hours a day, though it gets some non-direct sunlight from the windows on the room. I'm not sure on the water parameters--like I said, my mother has the test kit right now, and the odds on me getting it back soon are kinda bad, given how my mother is, but the last test about three weeks ago showed no ammonia or nitrate, and I think around 30 ppm nitrate, though I could be wrong about that. It wasn't anything alarming, though.

[nitrous]

well my blue green algae was cured by 3-4 days of a blackout, also how many watts of light is it you have?

[Devilishturtles]

Do you ever clean under your undergravel filter? Also, do you have any other filtration on your tank besides the undergravel filter? That could be one cause as to where it is getting its food source from. It usually grows in areas of high nutrient and low flow, aka a clogged undergravel filter.

My suggestion would be to either get yourself an HOB filter altogether, ditching the undergravel filter, or if you want to keep the undergravel filter, add an HOB or powerhead for flow, and make sure you clean under it a bit more diligently.

Also, blue green algae = red slime algae = cyanobacteria. Can be red, blue, green, even purple.

HTH

[HannahJ]

Well, I have an undergravel filter since that particular tank has bettas in it, and they seem to be stressed by even the lowest current setting on a hang-on filter. Do you have any directions or an article you can point me at for cleaning under an undergravel filter? I usually just give the gravel over it a good vacuum once a week or so.

As for the wattage of my light, I honestly have no clue. The light came with the tank (it was a garage sale buy) and I couldn't find a wattage anywhere. It's a long tubular light that seems bright to my untrained eyes, but that's all I could say.

When you recommend a blackout, do you just mean leaving the tank light off or actually doing something like putting a blanket over the tank? Would that stress the fish?

On a side note, purple algae sounds like it would be more cool than trouble.

[Devilishturtles]

Well, I have an undergravel filter since that particular tank has bettas in it, and they seem to be stressed by even the lowest current setting on a hang-on filter. Do you have any directions or an article you can point me at for cleaning under an undergravel filter? I usually just give the gravel over it a good vacuum once a week or so.

Sure. Since there is an empty area between the bottom of the tank and the gravel, stuff will accumulate there over time. To get rid of the junk, simply take a clear piece of hosing and put it down the intake tube of your undergravel filter. Try and slide it under there, and suck out some of the gunk. You can buy a cheap bulb to use to suction the water. They usally sell them in the automotive area of most stores, for suctioning gas with.

I wouldn't worry about your light wattage. It would only be a factor if you had high output flourescents on your tank, and not a stock set up.

About a blackout, that is exactly what it is. Completely covering the tank for 3-5 days and not letting any light peek through at all. No feeding the fish either. They live fine though it. To be honest, I'd see how much gunk you pull out of your UGF first. Also, what kind of pump are you using to power the UGF?

Purple was bit of a stretch, it's more maroonish.