c'mon nige now you finally got on the thread and all we get is smalltalk, what about the asm amounts?
Sorry Chug...my usage is pretty similar to others on this thread. When I first started I was consuming 3.5lts of ASM for a 150lt batch. Typically 3lts for stage one and the balance for stage two.
Using a double glycerine wash as a pre-treatment I now use 2.8 as a first stage and then about 200-300ml for stage two. It's all down to stage 1 dropout.
At 4-4.5ppl I reckon it's pretty good value.
Adjustments to the amount you use on stage 1 are best judged on the amount of dropout from your first 10/90. I think, personally you should aim for 10-20% unreacted. Anymore than that I would recommend an increase in the amount you dose.
I've had some difficulties when the calculated dropout from stage one reached 40%. This normally resulted in a 3 stage process rather than a 2 stage to acheive a clear pass on the finished raw bio. Hence the aim for that in the above paragraph.