Brown algae

[vtnhtr]

I have brown algae on my sand and my walls. What causes it and how do I get rid of it? This is in my 180gallon tank. I do 25% water changes weekly. I have a wet/dry filter, an xp4, and a magnum 350. Could it be that the bulbs on my t5 lighting is losing its intensity?

 

[BigCountry]

did the tank just come out of cycle? its more than likely not algae, it's "diatoms" - which come from high nitrates and phosphates or silicates in your tab water, assuming you are using tab water.

some diatoms are normal right after a tank cycle. they need to eat up all the silicates and then they will cease to grow. you can speed the process up by dusting the diatoms off the sand and glass, then doing your water change (after you have stirred it up, suck it out etc), then kill your lights.

unfortunately, if you keep using tab water though, you might be fueling the diatoms with fresh silicates every time you do a water change

 

[cacichlids]

Brown algae (diatoms) is common in new tanks (less than a year old), it goes away on its own as the tank matures. I've found that changing the substrate (sand) usually causes a brown algae bloom, possibly due to the new sand leaching silicates into the water. It's also related to low lighting conditions or old bulbs losing their intensity like you said, and it usually gets replaced rapidly by green algae when the light output is corrected.

Nerite snails will leave your tank spotless in a matter of hours and keep it that way until the problem is fixed.