RCS cave?

So I'm planning on getting some RCS for my 10G. I know that they need a cave to hide in that my fish can't get it. Can I just take a flat rock from my yard and prop it up with another rock? If so, how do I clean these rocks so that there's no funky stuff on them and so there will be no chemicals etc. in the tank with my shrimp and fish?
I think washing it in dawn dish soap is a bad idea because I'm sure it leaves a residue behind = no good for shrimp or fish.
Do I just wash it under super hot water?
I need help constructing a home for these little guys.
Thank you so much.

 

What I do is to leave the rocks in a bucket with diluted bleach for a couple days. After that, I drainthat water and put water back treated with double amount of required conditioner and put the rocks back in for another day. Never had problems doing it like this.

 

Definitely NO soap

I'd go the hot water or bleach solution route. You could boil them if you want to be sure as well, but don't heat the water too fast (nor pour cold water on them to cool them off faster either) or you could have a case of the 'exploding rocks'. Also I would do the vinagar test on them.... if they fizz when you pour vinagar on the rocks then they aren't the kind you want.

 

Unless you're just set on rocks, I made a coconut cave for my shrimp and it turned out really nice. Was actually much easier than I thought it would be.

I think there was a post on these forums I got the idea from and followed(I can't seem to find it now of course).

You have to drain it first of course(screwdriver through the soft hole), then take a flat head screwdriver and hammer and mark along the middle. after you have it scored enough you just go deeper and eventually get brave enough to just crack it.

Next you just take that flat head screwdriver and get all the meat out. There's a bit of skin between the meat and shell that I found it easiest to jam into to get big chunk out with less work.

After you get all that meat out you can decide if you want to cut away the extra hairs and such. Then you decide where you want the entrance and take the hammer/screwdriver and chip it out.

After you get everything the way you want it you just have to boil it for a really long time, I kept changing the water every 20 minutes until it was fairly clear.

It can take some time but I think they turn out really well and since you have 2 halves you get 2 caves, some java moss on top makes a nice little home

Picture isn't the best and it's a little old the moss has grown a ton since then. Hope I could be of some use!

 

Good idea!

 

Those coconut caves are so cute! Very creative.
I like the rock cave idea because I can have it right up against the glass so I can still see inside the cave.

 

That coconut cave is awesome! Wouldn't it eventually rot though?