Midi Fader or Audio Fader When Setting Up A Mix

Sorry for asking this but not really finding any clear explanation.
When using midi tracks that are routed to Halion Sonic SE should I be using the main faders on the mixer or use the midi channel volume fader as far as I can see when the volume is altered using the main mixer faders, and you then move the track back or forward,the volume levels will not stay at the same level.
Can anyone let me know the the best way to set volumes for midi tracks used in conjunction with Virtual Instruments,many thanks

Just to make sure: you don’t mean Instrument track?

Fantom I import midi file containing several midi tracks,these midi tracks are automatically populated with a program sound from Halion Sonic SE using GM Sounds,I hope this makes sense,thanks

The MIDI volume faders are mostly a relic from the past. Use the audio faders.

I don’t fully grasp this statement. Care to expand?

I didn’t realise that I had to remove cc messages within midi list editor,I all appears to be fine,many thanks