Adding crushed shell.

na-h2o

New Member
Hi everyone,
I have a quick question. I have a relativly new tank but it has already cycled. Water chemistry is good. Amonia 0-ppm, nitrites 0-ppm etc..
I am not happy with the amount of crushed shell and sand in the tank. Would it hurt the tank to add another layer of media on top of the current media? Would it be safe to do it a small layer at a time?
Thanks
 

ed r

Member
You can safely add small amounts to the top of your substrate (1/4-1/2). Are you sure that you want to use crushed coral or shells? Most of us are going to considerable effort to get rid of the CC and establish deep sand beds. You might want to do a search on DSB before proceeding.
Here is a link to Dr. Shimek's site regarding DSBs.
<a href="http://www.rshimek.com/reef/sediment.htm" target="_blank">http://www.rshimek.com/reef/sediment.htm</a>
 

ruaround

Active Member
Adding more CC will be fine. A DSB is a great filtration method and substrate. There have been many many many successful systems that use CC and there will continue to be. If you like CC use it, just keep it vacuumed, get a solid clean up crew, and be sure not to over feed.
 

beth

Administrator
Staff member
IMO, you defeat the purpose and the extra expense of getting live sand, if you then top it off with cc.
CC is nice to look at as are course substrate such a shells, but the basically clog your filter bed, and make it very hard for infauna creature to do their job on the sandbed.
Up to you though.
 

frogger

Member
so is there a difference here between cc, crushed shells and aragonite? I got a bag that said aragonite but it has several very small shells?.?.
what did i get???
 
so it defeats the purpose of adding cc to sand but what if you want to add sand on top of cc? i have a 2 1/2-3 inches of cc. just wondering. thanks and sorry to take the post
 

ed r

Member
If you use the CC, you need to stay with a limited depth and perform regular maintenance by vacuuming. That can be and has been successful. A DSB is 4-6" of fine sand. As mentioned aragonite comes in various sizes. The size is much more important than the material. The DSB is not to be stirred or vacuumed. It should process the detrius and eliminate the nitrate without your action. It is your choice of approach. Just make an informed decision.
 

frogger

Member
OK, SO I AM A LITTLE CONFUSED. I AM GATHERING THAT CC AND ARAGONITE ARE ONE IN THE SAME.?.?.?
IF THEY ARE, I FEEL LIKE A NERD! I HAVE BEEN READING POSTS AND SAYING "WHEW, GLAD I DON'T HAVE CC!" LET ME KNOW PLEASE!
TANKS!
 

ed r

Member
CC and Aragonite are different materials, but may be the same size. As CC is made by breaking larger pieces, it generally has sharper edges. The critical feature in choosing material for a DSB is the grain size, not the material. You want a very small grain, .2-1.2 millimeters. If you pulverized CC, it would be usable because the sharp corners and large size would not exist. Silica sand in the appropriate size is also usable. Aragonite MATERIAL (in the appropriate size) is very good, but at the pH that saltwater tanks should be kept, the amount of disolved substrate material we can expect is insignificant.
I see your choice as a shallow layer of CC that you maintain, or a DSB of 4-6" that you leave alone for the infauna to maintain. Keep reading these boards. Don't rush your decision. If you are unsure, read some more, ask more specific questions. Where possible, look for scientific reference or support. That is why I give more weight to Dr. Shimek's books and articles.
Good luck.
 

fshhub

Active Member
actually cc is aragonite, but more of a coarser grade then aragonite sand
same material though, and with a dsb, you need smaller grain substance not larger
 

rattlyfuture

New Member
I bought a bag of LS and put it in the bottom of my 20g aqaurium. Is this sand fine enought to make a good DSB. Right now I have 1 - 2 inches of sand and was thinking one more bag should do it with 15 lbs of live rock. I have no other substrate in the tank.
 
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