Sand on Top of Crush Coral

[justin100]

I was told that having a sand base on top of crush coral helps as a filter for your tank. Has anybody heard anything about this? I want to know more because I am getting ready to switch over to sand. Yea I got suckered into buying crush coral as a beginner not knowing now i am paying the price. :(

[Ram_Puppy]

How big is your crushed coral media? A lot of the DSB prophets say the key to success is different sized grains of media in a DSB, if so, I would think your crushed coral is right up that alley. However, your crushed coral has probably been trapping detrius for the life of the tank, I am not sure I would want to simply cover it up with sand...

I am going to shut up and defer to one of the great ones.

[scuba_steveo]

The problem with covering crushed coral with sand is that the smaller grain size particles will make their way to the bottom and the crushed coral will end up on the top again. Best thing to do is take out the CC and add the sand you want. My suggestion: if your tank is small go with the arag-alive
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=C-ARAG-L-RS&Category_Code=Substrates
If you have a big tank it will be too expensive to do the entire thing with arag alive so do most of it with special grade reef sand and a few bags of arag-alive
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=C-RSAND40&Category_Code=Substrates

[captexas]

Steve is correct, all the sand will slowly filter through the gaps in the crushed coral and settle on the bottom. I mixed the fine sugar sized sand with some other "reef" sand when I started my first tank. After awhile, all the fine sand settled to the bottom. I hated having all the larger stuff on top.

[GaryP]

My preference is as Steve stated. My next tank is going to have a sugar fine bed covered with special grade. The sugar fine will provide a good biological media and the special grade on top will keep the sugar fine from blowing around. Burrowing critters will be able to handle both.

Gary

[StephenA]

Read this. This how I set mine up. I used a dense but fine sand on the bottom and a very light sugar sand on top. It's been up for about a year and they stay pretty seperate.

http://www.rshimek.com/reef/sediment.htm

[Ram_Puppy]

I would say rather than buy the arag alive, just get a live sand culture from someone in the club, much cheaper, much better.

[scuba_steveo]

Ram, I agree but you run the risk of flatworm or something of that nature