So I've been seeing brown spots on the sand the past couple days to a week now but today hit hard. The rocks themselves seem to be clear or most algae but the glass and sand in particular is covered. Should I be trying to get it out with a syphon or just let it do its thing? the tanks been running a little over a month and levels are ok nitrate around 5 phosphate is detectable but even hard to read with the low range kit.