substrate

[billyjoe]

I have 40 lbs. of cc and 150 lbs. of play sand which should i ues for a fish only 30 gallon tank?

 

[carrie1429]

IMO use the sand. It looks better and will not create a high nitrate like the cc. Uneaten food or waste goes into the cc creating nitrate while sand is harder for the waste to seep into.

 

[ed r]

I would no longer recommend using CC in any tank anymore. Some people do well with it, but I feel they would do better with sand.

 

[wrassecal]

Go with whichever you like best. I started with cc over about an inch of sand and got tired of all the gunk it caught and trying to keep it clean. I did not have nitrate problems, I switch to dsb only because I liked the look so much better. Don't mix them though. Also, you won't need 120lbs of playsand in a 30. If you go the dsb you'll nedd at least 20 lbs live sand on top to seed it and live rock. Here's a link that might help<a href="http://rshimek.com/reef/sediment.htm" target="_blank">dsb shimek</a>