Hi guys I'm planning on starting my second ever brew this weekend and want to make sure I get the temperature down as low as possible. I doing a Thomas coopers ipa with lme and hop bag. It's a warm weekend here in Sydney. An I ok using ice from my freezer? Or should I boil up some water first? Or can I use regular ice you buy from the supermarket or service stations? Should I use ice at all or us it a bad idea?