Given the responses provided and what seems to be a bit of a worried frantic sense to your posts, im gonna say that your best bet is to possibly find an experienced salty hobbyist near you to take the fish while you gather your bearings and get the tank properly set up. Being as to how its a 250g tank, repeated pwc's are gonna get expensive rather quickly. In order to successfully maintain these fish in a healthy environment, you are gonna need certain tools and gadgets. Those being a refractometer (to measure the SG or "specific gravity" of your saltwater mix, 1.022-1.025 is ideal) a master SW test kit ( stay away from API Nitrate tests) various measuring cups and a few 5g buckets. Now onto the tank. In sw, the optimum lr ratio is 1-2 lbs per gallon.. So obviously thatll put you at 250-500 lbs of lr. Id personally shoot for 375-400..