Cyano or Corraline ?

[Nonofr2012]

Hi Guys !

I have a question about my fish tank. I have this purple algea and I can't tell if it is Cyano or corraline. I though it was Cyano because it is on the sand.
So I tried to put the tank in the dark for 3 days and it didn't change at all (With blanket and stuff).

I tried with a seringue to remove it, it didn't work. I try to scrap it with my finger it didn't work. I can move the sand, but the purple sticks. Though I can scrap the plastic part fairly easy with my nails (Filters and stuff). I tried a toothbrush and I can remove some of it but I have the impression I remove the rock itself not the algae (Reaf Safe Rocks).

Tank information:

• 60g
• 3 fishes
• The tank is 6 months old
• RODI water
• Fish and Live Rocks only.
• I don't think I overfeed I'm extremly cautious.
• HoB Skimmer
• Filter with chemipure
• Change the water every 2/3 weeks (30 %)

Do you have other tests I can do?
Thanks a lot !

 

[beth]

Coraline consists of calcareous material so you won't easily get it up. Don't bother trying to scrap up cyano it will only make matters worse since you will just spread more of it around the tank when it is disturbed. How rapidly did this grow?

This doesn't look exactly like cyano to me, however. Cyano tends to form thick blanks of loose algae on the surface and is easily taken up or pulled off. I can't tell from the pic if the pink on the sand are just covering individual grains or is forming a blanket. In the absence of the blank algae I described, and slower growth, I'd rule out cyano.

 

[Nonofr2012]

It is really not a blanket on the sand. it is more like some grain of sand are pink and the others are not. It grew up maybe in 3/4 month (When I added snails, so maybe I had something coming from my LRS). Slowly at the beginning and it seems faster now.

Thanks for the reply, I really appreciate

 

[beth]

Do you have live rock? Or is that base rock in the pic?

 

[Nonofr2012]

It was a dry rock bought online on Bulk reef supply. I only have dry rocks in the tank. It has been cycled using a shrimp.

 

[bang guy]

Looks like Coralline to me. Cyano comes off very easily and comes & goes with the light, coralline will turn white if you put it in the dark but it takes a few days.