So I work at a petstore, and although I feel very comfortable talking about the more general aspects of fishkeeping (acclimation,nitrogen cycle,heaters,filters etc) I am struggling to remember the specific needs of each fish and which ones work well together. As well as a few other random things. In light of this, I have compiled a list of questions that I am commonly asked and I need your help to answer them. I know some seem like very basic questions but we sell hundreds of species and there is a lot I need to learn/reaffirm. So here it goes: 1. -What is the best “sucker fish” for smaller tanks(10/20 gallons)? 2. What is the minimum tank size for a BNP? 3. What fish work well with tetras? 4. What fish can go in an unheated tank. The only things I know we have that work are WCM and Paradise Gouramis. But I have heard that some tropicals can do well in cooler water? 5. What is the best fish for a small(2.5/5) unheated tank or bowl? I know its bad but we cant refuse customers and so I HAVE to pick a fish for them. Thus far I have been suggesting paradise fish 6. Do guppies have to be kept together? 7. What fish work well with livebearers? Schooling or solitary fish and which ones? Again, I know these questions seem very basic, but my experience is limited to just a few species and although I know I can give a decent answer to all the questions above, I want to make sure I give them the absolute best one. Thanks for any help!