I don't think Malaysia reefing society is as vibrant as singapore. Cheapest is to get from fellow reefer who frag from their mother colony. Get lesser polys and slowly grow them.
Ich aka white spot is like flu. As long the fish immunity is strong it will not be affected by it. So keeping good water condition is important. Garlic also boost immune system.
Rocks are technically dead, live rock is 'alive' because of the bacteria for nitrification. A tank which is 3 months old and no algae growth seem weird. Tested your water parameter?