What combos can I have in my small reef? I have a 75 gallon with a 20 gallon sump. I was looking at the kinds if relationships that would be cool to watch. I can only think of three. Get a goby/shrimp combo, clown/anenome, I also saw a hermit crab anenome combo on live aquaria. I understand that just because you buy the creatures it isn't guaranteed that they'll pair up but what other symbiotic relationships can exist and be observed in the home aquariam?