Deep Sand Bed Overkill?

[karlseith]

I've had a 30xh reef set up for about 2 years now. In the tank their is a DSB of about 6.5 to 7 inches and about 5 to 6 inches in 20g refuguim. After about 3 months from setting up the tank I have never registered any nitrates in the tank and I have used several different test kits. However I only notice activity(coloration and worm tubes) about 4 inches down in the DSB. I want to upgrade to a 75 soon and was wondering if the bottom half of the DSB is just going to waste? In which case I will just go for 3 to 4 inches. Any input would be appreciated.

Thanks
Karl

 

[midiman]

Of course it really wouldn't be a "DSB" without that bottom half!!

The purpose of a DSB is to provide areas of low or nil oxygen for the conversion of nitrate to nitrogen gas. Seems like your DSB is working as intended.

 

[Thumper]

Sounds like it's working as prescribed, I wouldnt change a thing.

 

[canada911]

Is it that usefull? I also have a 30gl for 4 years and I only have about 1" of sand... I also NEVER saw any nitrate...