DSB still has no color below the surface?

[todd22]

It has been 6 monthes since I set up a DSB in my sump/refugium and I still do not see any algae or bubbles below the surface of the bed. There are plently of critters running amok on the surface, but I am wondering why I see no signs of life below (except worms). I have been running a skimmer and all my tank is flourishing. Recently I removed the skimmer because it was not removing much waste, but am now concerned of the effectiveness of my DSB. Could the skimming be removing all of the Nitrates before the sand gets a chance to? Or is this typicall of DSB's not to display any color or bubbles? Any insight would be greatly appreciated.

 

[DK]

Without much in the way of details, I would venture to say - be patient. If you have a light bio load maybe there isn't much nitrate to get rid of. Since my current nitrate levels are so high, I do see plenty of bubbles in my dsb's but mostly in the ones over a year old.