50/50 sphagnum peat/perlite or silica sand. You can also use LFS (long fiber sphagnum) by itself but IMO the roots will intertwine in it and make it harder to separate them if you ever do a complete media change which is recommended every 2-3 years due to mineral buildup. Yes you're going to have to use distilled or RO water if you don't save rain water. I now save water via a 55 gallon drum. It is possible to distill your tap water but hardly worth it. It will cost more in gas/electricity than just buying the water.

So i am moving my VFT outside and hardening it off. it seemed to be doing okay indoors for a few months but then the leaves started turning black and mushy and dying. i am trying to save it. there are still quite a few green leaves and stems on it. Ive only had it about 5 months and it is in the small plastic pot that it came in with that same potting soil. i water it with only distilled water keeping the soil moist. i read that they need high humidity levels and that they normally live in bogs so its pot should be submerged several cm in distilled water at all times mimicking it’s natural habitat. I’m not sure where i read this but i have been doing this. Now im worried that i have drowned my plant. should i repot it in perlite and sphagnum moss and move it outdoors?

The advice of not letting your VFT flower is always suggested because most people are not experienced or are new in growing CP, so these people barely have their VFT thriving. Flowering takes a lot of energy and if your plant is week, it can die. But if you have your plant growing very vigorously, theres no problem. I always let them flower, never had problems. When I was a beginner, of course I lost my pants until I was told to cut them off. Now I have no worries letting them flower. I had one VFT grow a flower stalk this late of the year but once I started to induce dormancy, the stalk aborted and died. That VFT is now dormant. To induce dormancy, just place it in a cool part of your house and give it less light. Now, most summer leaves will die and stop functioning, also your VFT will start to produce some smaller traps with sluggish movement if you trigger them. Those are winter leaves. Once the plant is dormant, cut down on the amount of water, just keeps its media moist to keep the bulb from drying out. I keep my dormant bulbs in a pot and simply place it in the coolest room next to a window. They will receive some sunlight but its not enough photoperiod to break their winter dormancy. I always let my VFT grow on the same media for 2 years before transplanting them on a fresh media. Or you can dig out your bulbs after it has become dormant, cut the old leaves to avoid rot, wrap it with moist LFS moss to keep the bulbs from drying out, place it in a Ziploc bag, and then put it in the fridge (not the icebox!). Always check now and then to make sure you keep the LFS moss moist but not wet and you can check on the condition of your bulb. The bulb should be white and crispy. Come spring you can plant them on fresh media to begin its new growth season. Good luck!

I would suggest either putting it in the fridge where temperatures are cooler, or just setting it outdoors if temperatures reach the 40-50F temperature range because venus fly traps and some other carnivorous plants need a dormancy cycle in order to thrive and put out more traps. I think the chilling requirement is 8 weeks for VFTs, but you should check the internet to find out. I'm in a cool climate so I put mine under tarps where they get near 20 weeks of chilling hours, but they need the rest at this time of the year in order to restore their growth hormones required for further production. Here is a link that might be useful: