Hair algae growing on my urchins

sherb · Dec 31, 2022

I've got two small pencil urchins that have developed a difficult case of hair algae on their spines. The algae has also appeared in a few other places on my rocks and it's no problem to keep those spots under control with a toothbrush, but it doesn't seem like a good idea to use manual removal directly on fragile urchins. Using peroxide on them also seems like a bad idea.

Some research indicates mixed results with fluconazole and/or Vibrant at removing hair algae generally from a tank, but I'd prefer not to use medications as a first resort. Any other suggestions? Just keep my nutrients down and wait it out?

Other info: Tank is just over two years old and has a wide range of fish and inverts and soft corals. Lighting is AB+ for twelve hours a day (100% for 10). Phosphate is 0.05, nitrate is 16.9 (Hanna kits).

Here's one of the urchins hanging out with his buddy:

A sample of the algae elsewhere in the tank:

Bucs20fan · Dec 31, 2022

Likely your nitrate and phosphate are actually much higher, the algae is using it as fast as it can, what you are measuring is what the algae isnt using. Your nitrates are probably in the 50's and phos is probably close to .5. You can use any of the nitrate or phosphate reducing resins, they are generally pretty safe as long as you keep track and dont bottom out. GFO will strictly attack the phosphate.

monica HHF · Mar 5, 2023

If you

Bucs20fan said:
Likely your nitrate and phosphate are actually much higher, the algae is using it as fast as it can, what you are measuring is what the algae isnt using. Your nitrates are probably in the 50's and phos is probably close to .5. You can use any of the nitrate or phosphate reducing resins, they are generally pretty safe as long as you keep track and dont bottom out. GFO will strictly attack the phosphate.