Aug 24, 2009
i have noticed 2 kinds of algae in my aquarium and i am having trouble identifying them

1) around 2 weeks ago i added new liverock to my aquarium and within a few hours bubbles started forming (a good sign [i hope]). although the people i bought it from said red coraline algae would start forming with-in a week, it doesn't look any different (with the exception that it is a little darker in color). any way, 3 or 4 days ago i noticed that the sand in the corner of the tank was turning red. when i check the day after there was a bright red coloration in a big oval on the sand. i assumed it was the coraline algae forming since the man said it would be red. this morning when i checked all the sand on the whole left side of my tank was red and none of it was on the liverock. i realized that it probably wasn't coraline and tried hard to find out why it was their (and get rid of it). it almost looks like Cyano but it's a realy bright shade of red-orange (unlike the purplish-red pictures i've seen). i have no phosphate in the water (says my test kit) and i've removed the sand containing the algae (thats why there are no pictures) and resorted to leaving my lights off for the next couple of days. i figured that if i used an algae killer it would destroy any progress my liverock has made so i haven't used anything.

2)my fish food comes out of the "shaker" fast so every now and again their is a little surplus that sits on the ground. for a while i though it either dissolved or one of the fish ate it when food wasn't available, but yesterday i noticed that in fact it was just being covered by something. looking further i learned it was a clearish white colored slime of some-kind that cultured into strands, almost like hair algae but much shorter and thicker. i've only found this algae on the bits of food that don't get eaten, so if i had to guess i'd say it was a form of slime mold (which coincidentally is only found under water).

can you identify either of them and is there any way to treat them without killing my liverock?


Certified Ceph Head For Life
Staff member
Sep 4, 2006
Gainesville, GA
The red definitely sounds like cyno bacteria. If you can't control it by removal, there is a product that I have never had any problems with called chemiclean. I use far less of the recommended dosage and usually put it in my filter sock but have put it directly in the water for difficult cases (dissolve first if putting it in directly). It takes a few days but works and I have never lost anything using it.

The only time I have had white slime was very recently in my last remaining FW tank. I bought Tetramin from the grocery because I had run out of flake and had slime all in the bottom of the tank (I don't use flake in the marine tanks and feed frozen Cyclop-eze and mysis instead). The only fish in the tank died. He was 5+ years old (ie with me over 5 years) and it may have been his time and the problem with the fish food may have been that it was old (given where I bought it) but I would suggest tossing your flake and trying a new batch or switching to frozen.

Members online

No members online now.

Forum statistics

Latest member

Monty Awards

TONMOCON IV (2011): Terri
TONMOCON V (2013): Jean
TONMOCON VI (2015): Taollan
TONMOCON VII (2018): ekocak

About the Monty Awards