Quote Originally Posted by Tom Hoskinson
Lee is right, IMO. If you haven't enough exposure in the shadows to record the detail there, tweaking the development is not going to help much.

Soaking in the used pyrocat to increase overall stain is probably not going to work well - and why would you want to? What you need is shadow detail - not overall stain.

You might try semi-stand development for 16 to 20 minutes at 70F with a 2:2:100 dilution of Pyrocat (I do this with Kodak TMY 400). That should raise your maximum densities a bit.
I agree with previous comments by both Lee and Tom. I think you are under-exposing the film and in the best of curcumstances HP5+ is a poor candidate for push developing. A better film for this would be TMY (Tmax 400), but to hope for a real gain of one stop in effective film speed is probably expecting too much.

Finally, semi-stand development will produce maximum effective emulsion speed but don't expect a real increase in effective film speed of much over 1/4 stop. Unfortunately most of the film speed is built into the emulsion and developers and type of development play a relatively minor role in increasing EFS.

Sandy King