So only one of each right? Never had experience wth swordtails but I understand they like ots of plants and your lemon will like sand and lots of rocks. Possible? yes. not sure how happy they'd be but perhaps try to plant enough plants and provide the cichlid with rock caves and I'm thinking they'd be fine. Lemons are very pretty and not very aggressive( given the right tank mates)Is it possible to keep a Lemon Cichlid with a swordtail? I'm setting up a 30 gallon tank and want to keep both.