Tank mates for my 2 black moor

[Guest DeadpixelLady]

I have a 35 gallon tank. Recently set it up. I’m quite happy with my two black moors but my husband wants to add just a few more fish to make it more diverse. I know that my tank is pretty much booked so no more gold fish. BUT I was wondering if there’s an  exception for medium/smaller fish? I looked everywhere it seems controversial for what kind of fish that would do well with goldfish. Can anyone give me an actual answer for what fish would work or have had experience? Thank you! 

[FishyMandy 6,260]

I wouldn't add anymore fish, anything small would be at risk of been eaten. Once the moors grow up the tank will look quite full