I want to start a salwater tank

A 30g tank will support about 8 inches of fish total. As stated above, most LF will outgrow the tank. I know a guy who had a standard LF in his 55 and the fins touched both sides when it swam across. He had to upgrade tanks when it grew to size. I wouldn't put one in anything smaller than a 120g, but that is just me. They need a lot of room.

Base rock is the same as live rock except without the beneficial bacteria or unwanted hitchhikers. As your tank matures over the 12 week cycling, the bacteria will take hold in the rock and it will turn into live rock. That is the cheapest and best (IMO) way to go. Wish I had thought of it when i first got into this. I could have saved $600 on rock alone easy.

Timers on lights are good. I used to do that, but have chosen to do it manually because it requires me to attend to my tank first thing in the morning and last thing at night.

 

I completely agree, 30G is way too small for a lion of any kind. I only had my volitan lionfish in my 20G for 3 months while my 150G was cycling. Even then, he was onlya baby at 2-3" long. Volitans can grow to 18" long. Even a fuzzy dwarf can get up to 12" long. The smallest lions will need at least a 50-60G tank to thrive. And as the saying goes, "if it can fit in a lion's mouth, it will become it's next meal."

 

im not gonna say it can't be done like some of the other people, but it will be difficult with a newly established tank.
only a dwarf lion can be kept in a 30. and i wouldn't have any other fish besides that one because the dwarf will put off a huge bioload since theres a 95% chance it will need live food. i would also get a refugium to help remove some of the waste.

edit: you best bet is a fu manchu lionfish. its a pretty cool looking fish check it out.