Black makes them very dull I had black sand and it was killing me made my bichirs looks plain but now i have gone to slate rock bottom and am getting higher contrast as it has shades of clack grey and burnt orange in it. I would go red but i cannot find the color red i like like they have in asia. Here the red is just not right for me its too red not the right shade. look forward to pics mike.
The most desirable substrate for bichirs in Japan and Singapore is red quartz. If you see it dry, its actually quite brown. under T5 lighting its very brown too. Only under LED white lighting do you see a purer red. So in conclusion. Any tan, reddish, brownish substrate will do. Just make sure your bichirs can't eat it cos they can die from that. You will get the best out of bichirs using that. Mix in a bit of black like bro Tokyogasmask suggested to me some time back, it will get for greens up. Avoid white as a main colour as it kills any colour in the bichirs.
That is what I have learn so far. Hasn't really gone wrong.
