Help...Too much brown algae

[bonnethead]

My 180 gallon tank is building up brown algae at an alarming rate. Each day I have to clean the inside glass and the white sand is always brown. It is a new tank (only a few months old), but was set up with established live rock. I have metal halide lighting X 9 hours per day. Is there a simple solution? Thanks

[Billybeau1]

It may be just a new tank syndrome bloom. Have you checked your phosphate levels ?

[bonnethead]

That's what my local fish store told me, but how long will it last? Phosphat is ok...

[Billybeau1]

Dont know. Varies with each tank. Give it a couple of weeks. Maybe cut back on the lighting a little until it passes.

[boxfishpooalot]

more than likely its diatoms. They thrive off of silicate and phosphate, as well as nitrates too.

Chances are your sand has a signifigant amount of silica in it. Which must be available to the diatoms. Randy shows how silica can be released from both calcreous sand, and silica sand here:

http://advancedaquarist.com/issues/jan2003/feature.htm

from it:

From these experiments, I conclude that:

1. The “silica” play sand that I purchased from Home Depot can substantially raise the dissolved silica concentration in seawater.

2. The dissolvable portion of the silica sand cannot be completely removed by several rinses with either fresh or salt water, although it may be decreased somewhat by that process.

3. Southdown calcium carbonate sand (likely aragonite) can release soluble silica, but about ten fold less than the “silica” sand.

[Randy Holmes-Farley]

Reducing nutrients and waiting are good advice. :)

[carman9941]

clean-up crew, and cut back on photo period