sorry it took me a while to respond to the posing to respond and condense aquarium care for euphilla species. this is quoted form the reef aquarium
Once established,all Euphilla species are hardy.with the frogspawn being the hardiest and the torch being the most sensitive with the rest falling between. all require alot of room for expansion. allow 6 in around the skeleton to avoid stinging neighbor corals. sweeper tenticals are regularly formed by Euphyllia spp.,and they may span 1 ft or more in search of a targeted neighbor. euphyllia should onl be maintained in a large aquarium unless one wishes to keep only Euphyllia. in a small aquarium, less than 50 gal most euphyllia will grow too large with in a year. In fact, it would be preferable if collectors would choose smaller specimens only.
Most euphyllia species are compatable with eachother,which means they can be placed adjacent to eachother, allowing the expanded polyps and tenticals to mix. this creates a spectacular display. torches are the exception to this rule. it is not as com patable with other euphyllia species. it can touch but fares much better when it is not crowded by other species..
i hope this will help you out with your question. like i posted before I've kept both together for years and even have pictures to prove it. Any one who had seen my tank knows all i keep are lps corals. i have grape, fox, frogspawns, torches, pearl, plate, cups, swollen brain, hammer.
with such a small aquarium you should try sps corals since your tank has such limited space. you could get a much wider diversity of corals. i don't like to discourage people. but if a brown jelly broke out in such a small tank you could loose the whole tank in less than 24 hours.