brown algae/slime

[num54]

Hi ive got a 100g tank ive got some brown slime/ algae growing out my rocks i was told i could have hi concentrates of phosfates i just checked it and it is at 0 phosfates what could cuase this ive been doing 20 gal water changes every week and been scrubing the rocks with a tooth brush any advise

 

[nater]

a picture would help , it's probably dino bacteria. how old is the tank?

 

[Angels 2010]

how old is the tank?

 

[num54]

the system has been runing for about 2 years now

 

[CHALICEKEEPER]

Could be the water you are adding?

 

[Ike]

Don't rely on a phosphate test kit, if you have nuisance algae you probably have phosphates regardless of what your test kits says. You could be dealing with dinoflagellates, but a picture or a better description is needed before we can make an educated guess.

 

[Ike]

a picture would help , it's probably dino bacteria. how old is the tank?

Don't confuse dinoflagellates with typical cyanobacteria, different things with somewhat different "cures".

 

[num54]

cant post a pic at this time

 

[ReefGeezer]

Dino's create a slimy or stringy (some say snotty) coating that has bubbles in it. The coating usually thins when the lights are off and the bubbles go away. When the lights are turned on, the coating and the bubbles start to increase.

Cyano will be a flat more algae looking coating with only occassional bubbles in it. It also tends not to thin nearly as much when the lights are off.

Both of these are bacteria that are photosynthetic (sp?). They can also present themselves in different colors according to light and nutrient levels. These bacteria can survive on many different organic compounds besides phosphates. The first step in resolving the problem is properly identifying the bacteria.

Also, diatoms show up as a brown coating on substrates. This is usually more like a dusting than a coating. These are single celled algae that are not photosynthetic. Silicates are the fuel for diatoms.