You must always cancel your streams before your Super Token balance hits zero or your buffer will be lost.
Make sure you understand this before you start your first stream.
Streaming tokens using Superfluid requires you to lock a certain amount of buffer or deposit which is taken out of your balance.
The parameter for this buffer is currently 4 hours' worth of the streamed asset on most mainnets, and only 1 hour on testnets.
On Ethereum mainnet, the buffer has a minimum value configurable per token by the protocol. The buffer is always correctly displayed in the UI when you start a stream.
e.g. if I am trying to send a stream of 1 MATICx per hour, I will require 4 MATIC as a buffer. The buffer is immediately taken out of my balance and held until I cancel the stream.
This means that short-term streams are rarely a good idea as a significant portion is held as a buffer.
The buffer is an incentive mechanism to ensure users cancel their Superfluid streams, to prevent the output stream from ever surpassing the sender's Super Token balance.
You will see a warning every time you stream and must check the box to proceed. If you allow your Super Token balance to reach zero, you will lose the buffer. It is your responsibility to cancel your stream manually before this occurs.
If your balance reaches zero, your stream will be liquidated and your buffer will be claimed by a Sentinel as a reward for manually closing your stream.
If you see this alert in your activity history, then you have lost your buffer. Unfortunately, there is no way of recovering lost funds if you ignore these warnings.
You can learn more about buffers and solvency in the documentation.