Describe the bug
Was able to pump mercury into a Sophisticated Backpack(SB) however after pumping it out am no longer able to pump back into back

To Reproduce

Steps to reproduce the behavior. For example:

1. Create Mercury from molten cinnabar
2. Pump Mercuy from bubble cap into SB Iron backpack.
3. Pickup Backpack and move to a new location
4. Pump Mercury into create fluid tank.
5. Reverse pump and nothing happens.

Expected Behavior

It should pump the fluid back into the backpack.

System Information

• Destroy 0.0.8
• Create version 0.5.1f
• Sophisticated Backpacks 3.20.5.1044
• Sophisticated Core 0.6.22.611

Mixtures can't really go in other mods' Fluid Tanks, as indicated in the Vat ponder.