View Full Version : ID This Algae Please

05/28/2017, 06:57 PM
It is filamentous and purple under white light (see photos). It grows very quickly, covering the sand bottom in a day. it grows at the bottom of the aquarium and seems to grow equally well under Kessils when they are high intensity and colour and when both are low. I also have actinic and purple T5's.

When stirred, the algae breaks apart as easily as cyano. Chemiclean did not work. Nor did spraying the algae with air, which broke it up but did not kill it (proving it is not sponge). It is slimy to the touch. Phosphates and nitrates are regularly monitored and have been at zero for a long time. I run GFO and vodka. I feed a combination of frozen shrimp, spirulina flakes, reefroids and Reef Chili.

210 gal tank is 2 years old. Mostly SPS. 1% continuous water change/day.

Any help in identifying and eradicating the scourge would be most appreciated.

05/29/2017, 02:23 PM
Seems like very vigorously growing cyanobacteria.

Michael Hoaster
05/29/2017, 06:03 PM
I vote cyano as well. But chemiclean did not work? I combined CC with a four day black out, and that worked. I also had plants to compete for nutrients.

BTW, I think carbon dosing may have triggered my cyano outbreak, so you may want to suspend vodka until this is resolved. Good luck to you!

05/30/2017, 08:30 PM
Yeah, I did 2 rounds of Chemiclean and not a single cell died. I've used it before on cyano with great success. I'm not sure I can do an effective blackout because there is ambient light in the room. As well, I have lots of SPS that might not like me very much after 4 days with no light. I also have lots of plants in the sump downstairs to compete for nutrients and it is growing nicely.

Interesting thought to stop the vodka for a while. I could try that.

Michael Hoaster
05/30/2017, 08:50 PM
If chemiclean did not work, it must not be cyano. Yeah, a blackout is probably not an option for you, unless you can remove your corals to another tank.

Well, I guess it's just a purple algae. The usual algae suggestions would then apply. Manual removal, water changes, also try pruning back the sump plants. New GFO, less food, etc. Mollies may eat it. Pods, live sand, oh, and turn down the blue light. Algae can access iron better with blue light.

06/19/2017, 04:04 PM
It does look like cyano. Very similar to this.


How's your flow on your sand bed? Also, for me, I noticed that my return flow was not sufficient and it wasn't allowing enough contact with my nutrient export media (bio-pellets, chateo, gfo). After increasing the flow, cyano on the sandbed went down significantly.

06/29/2017, 05:36 PM
That is cayno, do not use chemo clear if you have corals, i had the same issue and used a product that kills fin rot , cayno is a bacteria if you use something that kills bacteria on fish it will kill the cayno and no hurt your corals. I have used this and it worked great . I also used the chemi clear and it almost took down my whole tank. It killed all my fish and it took 2 months for my corals to come back.