Help identify purple algae - cyanobacteria or other?

[insanelogic]

Hi all - I have this purple-reddish algae covering all my rocks and filter equipment. I have read about cyanobacteria and coralline algae, but this algae does not seem to match either description. It spreads fast on rocks and hard surfaces but seems to stay away from my crushed coral substrate. It does not peel off or really come off at all, only small bits when scrubbed HARD with a toothbrush, but it is not hard like what I've read about coralline algae. Instead, it's this soft purple algae that holds on for dear life. From what I have read, cyanobacteria tends to peel off from the rock, while coralline is more of a hard coating, this doesn't really fit either category. Any help is appreciated!

 

[Sophie"s mom]

if you can just blow it off with a turkey baster it is cyano, touch it, it could also be a sponge of some sort.

 

[insanelogic]

if you can just blow it off with a turkey baster it is cyano, touch it, it could also be a sponge of some sort.

It will not come off with any sort of blowing, even with hard scrubbing only the weakest parts come off. When I touch it it just feels soft-ish, not slimy or too slippery and none comes off with my hands. - I should also add that whatever it is never fully comes off. It always has a layer left over unless it is bleached. My tang also eats what he can get off.

 

[Sophie"s mom]

It will not come off with any sort of blowing, even with hard scrubbing only the weakest parts come off. When I touch it it just feels soft-ish, not slimy or too slippery and none comes off with my hands. - I should also add that whatever it is never fully comes off. It always has a layer left over unless it is bleached. My tang also eats what he can get off.

Sounds like either a sponge of some sort, or maybe some type of macro algae then. Definitely not cyano! Which of course is a good thing.

 

[insanelogic]

if you can just blow it off with a turkey baster it is cyano, touch it, it could also be a sponge of some sort

Sounds like either a sponge of some sort, or maybe some type of macro algae then. Definitely not cyano! Which of course is a good thing.

Great! It doesn't seem to bother too much as long as it won't throw the tank off balance or hurt corals. I'd like to remove it from some of these rocks as it covers all of them and I'd like to introduce corals, but nothing seems to work. Any ideas? This tank has had this in it for almost 5 years now, and I'm not sure what to do with it.

 

[Sophie"s mom]

Great! It doesn't seem to bother too much as long as it won't throw the tank off balance or hurt corals. I'd like to remove it from some of these rocks as it covers all of them and I'd like to introduce corals, but nothing seems to work. Any ideas? This tank has had this in it for almost 5 years now, and I'm not sure what to do with it.

Lets see if we can get @ISpeakForTheSeas in on this. They will hopefully be able to give you a positive ID, and maybe some advice. My concern would be it covering the rocks.

 

[ISpeakForTheSeas]

Lets see if we can get @ISpeakForTheSeas in on this. They will hopefully be able to give you a positive ID, and maybe some advice. My concern would be it covering the rocks.

OP, any chance you could get a microscope pic of a sample of it? The goal would be to see if it shows any spicules or not (basically, if it has spicules, it's a sponge, if not, it's something else).

Most sponges are described as rubbery and relatively easy to peel off, but it does seem to look like either a sponge or a fuzzy, red algae of some kind, so confirmation or rejection of either would be useful.

How to remove it effectively may depend in part on if it's a sponge or an algae (and on what kind of algae if it is one), so I'd see if you can't figure that out first.

 

[insanelogic]

OP, any chance you could get a microscope pic of a sample of it? The goal would be to see if it shows any spicules or not (basically, if it has spicules, it's a sponge, if not, it's something else).

Most sponges are described as rubbery and relatively easy to peel off, but it does seem to look like either a sponge or a fuzzy, red algae of some kind, so confirmation or rejection of either would be useful.

How to remove it effectively may depend in part on if it's a sponge or an algae (and on what kind of algae if it is one), so I'd see if you can't figure that out first.

Sure thing. It's not a great photo but I took 2 at different zooms.

 

[ISpeakForTheSeas]

Sure thing. It's not a great photo but I took 2 at different zooms.

Sorry for the late response - been busy. I don't see anything I could confirm as spicules; it's possible but seems somewhat unlikely to me that this could just be a cluster of spongin, so I'm guessing this is a red turf algae of some kind.

Urchins may help, or you could try a variety of manual/chemical removal methods such as scrubbing with hydrogen peroxide. You could also try a pencil urchin - Eucidaris tribuloides - as those will eat pretty much anything (including sponges, which are the primary component of their wild diet in case I'm wrong about this not being a sponge); they're not reef-safe though.

I'm not sure what the best approach would be in this case.

 

[insanelogic]

Sorry for the late response - been busy. I don't see anything I could confirm as spicules; it's possible but seems somewhat unlikely to me that this could just be a cluster of spongin, so I'm guessing this is a red turf algae of some kind.

Urchins may help, or you could try a variety of manual/chemical removal methods such as scrubbing with hydrogen peroxide. You could also try a pencil urchin - Eucidaris tribuloides - as those will eat pretty much anything (including sponges, which are the primary component of their wild diet in case I'm wrong about this not being a sponge); they're not reef-safe though.

I'm not sure what the best approach would be in this case.

No problem! Hmm that's odd. I'll do some more research into red turf and see what I can find. I've heard that Mexican turbo snails can help.