Phoenix is my favorite lightning wallet! It is a node on your device, so it must be online to receive a payment. Darth’s advice to open one big channel and then manage liquidity within it, is the best way. I wish it did show exactly how much inbound liquidity is available. If you make a note of the sats received when you first open the channel, I think that can be used for what is actually available instead of the displayed total. (for example, receiving 1010101 sats should get you a 1000000 sat channel) As Darth said, receiving from on chain will open another channel, incurring another 1% fee, so try to avoid that. Paying to on chain only incurs a mining fee, but you do not get to set the fee, and it can be a little pricey. Probably okay for larger amounts though since mining fees are not proportional. In my experience, paying to on chain does not reduce the total channel balance which is good for preserving one nice big channel. Again like Darth said, do not spend all your sats leaving the whole channel balance on Phoenix’s side. I doubt they would tie up their liquidity for long, and would likely close the channel. Their website has a good FAQ if you haven’t seen it yet. Best!