crushed coral,live sand mix is hard

[csr1]

I might be in the wrong section for this but I don't know what to do. My live sand crushed coral mix which is only about 3 inches in some spots and 1/2 - 1 inch in others is hard. The tank has only been running for about a month and I do have a few eels in it but I was doing a water change and trying to suck up some of the algae on the sand and I actually had to beat on it to break it up. It was hard all the way through in most of the tank. I have never had this happen before.
Granted the crushed coral is from the previous owner but I rinsed it so thoroughly that I thought it would be ok.
Anyone have any ideas as to why this is happening or what I should do?
Should I take out all of the substrate and put in new? HELP!!

 

[lonestar]

Are you adding kalkwasser? I may be wrong, but it sounds like u are overdosing with calcium. That will definately make the sand clump together like big rocks. You should still be able to break them up some. If you are dosing with kalkwasser, I would consider going with a less mixture but keep an eye on your calcium level, dont let it drop too much.
Jeremy

 

[johnnysalt]

ok you guys, I can't believe I'm the first one to mention this...
csr: out of curiosity, WHO told you to combine both cc and live sand?!?!? One benefit of live sand is help reduce nitrates....which can be caused by detritus getting stuck all in the cc! (With the 2 types of substrate, you have a vicious cycle going on in there!)
If you have a 100% sand bed, which is more beneficial than cc in more ways than one, you won't have this problem.
My opinion...take all the substrate out, bag up the cc, sell it on ----, rinse your sand, add some more so that you get a 3-4" dsb.
John

 

[csr1]

Thanks so much for the help.
The guy at my LFS said that mixing would be ok. But I am finding out the hard way that it isn't. At least not for me. I am not dosing with anything right now. So it has to be just the mixture of the two. Granted the tank is only 4 weeks running but I don't think the substrate should be doing this.
I am going to take all of the substrate out and add nothing but live sand to the tank. I am going to try for 3". Money being what it is, I think I might try to find some of that play sand I read about and add mostly that then get some good live sand from somewhere and add that to give it a good start.
Thanks again for the help.