Substrate for apisto and other dwarf cichlid tank

[Cookie_apisto]

I am going to setup up a 40g breeder mixed dwarf cichlids tank including apisto, german rams and checkerboard along with some sterbai cory and some cardinal and I am not gonna keep any plants. Just spider woods and black lava rocks for decoration. I know sand is great for these fish but beside the sand is there any other substrate that is also good? I am thinking of black gravel or Caribsea super nature blue ridge gravel.

 

[Siggi]

Hi,
I'm not a very frequent visitor of the forum and normally only browse the 'new world cichlids' pages.
Now, I wanted to post a question and stumbled over this unanswered thread. That's not good.
I'm not an expert, but as nobody else has answered, I'll give my 'two cents', with an obvious answer (to me, it's obvious...)
In a breeding tank, NEVER mix more than one species at a time, specially tetras and cory's, as they most likely will eat all eggs or fry.