Any advice for developing hp5+ with Microphen?

Can I use Microphen for develop ilford hp5+ (asa 400)? Any advice?
Is Microphen good to develop Delta 100?

Or is better to leave it only for pushing process?

You certainly can develop HP5 in Microphen. My testing showed good gradiated negs at box speed. Admittedly this was home-brewed Microphen at 1+1. I got perfectly useable negs pushing HP5 to 800asa with the same soup. Couldn't tell you about Delta 100 I'm afraid.

Yes, you can develop both HP5+ and Delta at the rated box speed in microphen and get great results. You don't have to use is as a push process developer, though it tends to display a little bit more shadow detail, hence 'speed', than something like ID-11.

According to the datasheet, they BOTH need 6 1/2 mins in stock, so you can even develop them together
Personally I prefer to use developers diluted as a one shot. In 1+1 Delta needs 10 mins but HP5+ needs 12, for some reason, so you can't do them together any more...

Steven, is there an actual diference in the image result between developing with stock and 1+1?

Yes.

The solvent effect of the sulphite is dimished as the concentration goes down - so the grain increases (a bit). But, the developer can tend to get a bit softer - you get a bit of compensation effects (the highlights are a little less likely to block up for a given development time) and sharpness and acutance effects are likely to increase. This is true for most developers. Full strength (stock) gives the finest grain whereas progressive dilution makes the developer behave more like a high acutance, compensating developer.

But, the difference between stock and 1:1 won't be massive. Try stock against 1:3 to see more effects. Development times can get very long, though!

If you want maximum speed from Delta 3200 or something, then stick to stock. If you want to use it as a 'normal' developer, I personally think 1+1 or 1+3 used one shot is a good way to go, consistent and economical. At the moment I am using Perceptol which I dilute 1+3. Long development times, but lovely negatives!