hi everyone. i have just purchased a 530 litre tank for use as a marine tank. it just came with a tank and stand. What i really need to know is to keep it as a natural tank with live rock how much would i need of live rock & live sand. also would i need a certain heater, pump, protein skimmer and how many powerheads for that size of tank as it is quite large. i would really appreciate it if there any pro's out there who may be able to help me.... thankyou.. kelly