red algae....?

[marlin08]

I noticed this weekend that the lush green algae on the walls in my 150g outdoor (heated) stock tank had somewhat diminished and a reddish black flat algae seemed to be taking over....I thought I noticed a few dark spots a couple of weeks ago now it is all over the walls.
I'm attaching pictures. The first one is of how the walls looked up until this weekend. The second shows the red algae. The red algae actually looks black, only with the camera flash did it show up red.
I'm assuming that this is the dreaded red algae that is related to beard algae?? If so, from what I'm reading this algae is really, really hard to get rid of..this tank is well cycled and up to now has had good, green algae on the walls and bottom that the fish munch on....anyone have any suggestions other than scrubbing it out and starting over??

[Corrie]

marlin, I don't know what the dreaded red algae is, but that just looks like cyano to me.

Corrie

[marlin08]

most of what I read on cyanobacteria had to do with salt tanks and described it as red slime...didn't seem to fit as this is very flat and doesn't seem very slimy but I have no experience with it whatsoever so I could very well be dead wrong..

This tank is outside, understocked (4 goldies in 150g, 5 as of this past weekend ) heated to about 76, lots of circulation with a powerhead, sponge filter and pondfilter, weekly big water changes...
I will say that it has been cloudy here for weeks, not much sunlight but don't know how that would play into it
I've just noticed it's increased a lot in the last week or so and want to do something about it if I need to..

[small_ranchu]

It looks like brown algae to me.

[Corrie]

It's doesn't feel slimy, just looks that way.

Easy way to tell. Take your fingers and see if it comes off easliy.

[marlin08]

It looks like brown algae to me.

It doesn't really look like regular brown algae when you look at the actual algae ( as opposed to my pictures with color that's off ) - I've had that indoors when I was using the standard lighting that came with my 30g tank.
It doesn't look like the pictures of cyanobacteria that I've found but I'll keep looking. I just hate it's diminishing the nice green carpet of algae on the walls, whatever it is.

[marlin08]

It's doesn't feel slimy, just looks that way.

Easy way to tell. Take your fingers and see if it comes off easliy.

I'll do that this evening, I leave for work before daylight so it will be hard to see this morning.
Does cyanobacteria come off easily?

[bluebelly]

I get this in covered ponds with limited light, I remove covers to expose to full sun light and it goes away. I

[Corrie]

Does cyanobacteria come off easily?

Usually

I get this in covered ponds with limited light, I remove covers to expose to full sun light and it goes away.

That's exactly why I figured cyano first. Winter, less light and less water changes. Phosphates have built up, and cyano can get real dark red/brown like that.
Plus true red algae needs a lot of light.

[marlin08]

I get this in covered ponds with limited light, I remove covers to expose to full sun light and it goes away. I

Thank you, that would make sense.
My cover is clear plastic over a lattice frame and the lattice blocks some sunlight. Our weather has been unusually cold which limits the time I can leave the cover off. Need to come up with a better design next year.

Corrie, the light is limited but not the water changes or water quality. I am very conscientious about water quality and weekly changes. I've been out there in 30 degree weather with a hose run thru my kitchen window so I can match the water temps.
Yes, I'm nuts...

I tried letting them cool off early in the winter but our temps have been so crazy down here in Georgia that there were crazy swings back and forth. When the water stayed in the mid 60's for an extended time, I had 2 get red body sores ( aeromonas?) so I ran the temp back up and that solved that problem, or appeared to. Maybe will try again next year...

Thanks for the input, it is much appreciated :)