Can't add keyframes to Parameters

[photosbyiki]

tyFlow is history dependent. Each frame the particles are spread, the spread effect is added to the last frame, so they're spread further and further. If you want particles to return to their starting state, you need to store that starting state and then restore it each successive frame. You can do this using Custom Properties operators (set position on entry to vector channel, then get position continuously from that channel after that, prior to spread).

aah, that's what's happening.  Thank you so much for all this help.  I really appreciate it.  I can see that I have a lot to learn!

thank you so much