New sand over old crushed coral substrate?

[Ixmnrs]

If I have an existing substrate of very coarse CC, is it possible to add new sand substrate directly over top instead of changing it entirely? The problem is that the very coarse crushed coral (which I originally thought looked nicer, have since changed my mind) is too difficult to keep free of detritus. The basic setup is a 40 gallon hex with emperor 400 double biowheel with protein skimmer, 2 water pumps, 25 lbs of LR. Current susbstrate is about 1.5". 4 small fish, 1 shrimp and a few soft corals.

 

[jamal-188]

The CC will eventually work it's way to the top and you will have a layer of sand on the bottom with a layer of cc on top of it. You'd be better off removing it IMO.

 

[jackdp]

I'll second that. I even tried removing what I thought was "enough" of my old CC and put in LS and now I have spots here and there where all the CC I left has come back to haunt me. It doesn't really harm anything, it just depend on if you think you will mind looking at it.

 

[ImLookinForNemo]

I was going to ask this exact question on another forum ...when I first started my aquarium (and it's not finished yet, the only thing living in it is LR) I bought crushed coral for substrate. The only problem is, the coral isn't very finely crushed-is that ok? It's basically just pieces of coral and shell, and it looks fine-I have no problem with that...but would it be more beneficial in the long run to get rid of it and get something else?

 

[Ixmnrs]

After a while, the white coral chunks turn blackish-grey, and I think it's also not that ideal for certain clean-up crew inhabitants like sand sifting stars, gobies, etc.

 

[ImLookinForNemo]

If I don't change to a sand bed now, before I put in fish, will that mean I won't be able to get any starfish, gobies, or certain other inverts in the long run? If you were in my place, would you go ahead and change to sand? I don't know much about the live sand, what would I get if I did decide to change?

 

[Ixmnrs]

I'm not quite sure, we'll have to wait until someone who knows a little more answers.

 

[BillyZ]

Welcome to AquariumAdvice.com

LookinForNemo: If your tank has only LR and substrate, i would swap your substrate now. Swapping the substrate can cause your tank to go through another cycle. If done properly that can be minimized, but it is still likely. Because of that you would be much better off swaping the substrate before you add any other livestock to the tank.

Ixmnrs: the other advice so far is spot on. As far as gobies and sand-sfiting stars... you might want to re-think them. The gobies and Sand sifters are actualy eating the life forms in your sand bed when they're "sifting" the sand. The life forms in the sand bed are what make the sand bed work. If you like those animals you'll need to be able to supliment the life in the sandbed by replacing their number through a refugium etc. you can read a good amount of that info on here by searching in the salt water forums (search link is at the top)