Adding a School to an Existing School?

Are you saying 18 MORE danios? I wish I could find ones that have other colors. I have seen pictures of blue-ish ones..

I think he said 18 total.
 
Tetras, especially Cardinals are schooling fish, non-territorial, easy to maintain, will eat anything you feed them.
 
If you want some more colour in schooling fish congo tetra's especially the males colour up beautifully also rainbow fish. I have both in my 180g tank and they actually school together. As mentioned above the larger the school the better it looks, especially in a planted tank. JMO

As for feature fish that is a very personal thing depends on what you like personality/ colour etc. But with the schooling fish in your tank you will want to avoid fish that like to eat smaller fish. I once put a school of 20 neon tetras in one of my tanks not realising that my 14" BKG would make a meal of the during the night. Only took him 3 days to eat the lot.

Cheers
 
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