recommend slow or fast flow rate?

[miro2009]

I am tryting to develop an RPC method for analysis of a certain protein in heavily contaminated fermentation media samples, I'm using a C18 4.6x250 mm column and finally reached 2 gradients with good separation profiles, but one with a flow rate of 1ml/min, the other 0.5ml/min offering higher peak signals for the protein of interest due to the slower flow rate and less eluent dilution. The question is why flow rate 1ml/min is always recommended for this size of columns? and is it acceptable to use a method of 0.5ml/min for routine analysis of these impure samples, and any required precautions for slower flowrates like extending regeneration and reequilibration at the end of each run?
awaiting your comments and opinions

[tom jupille]

1 mL/min is a "convenient" flow rate, but there is nothing wrong with dropping the flow, especially with big molecules, which diffuse slowly.

In gradient LC, what matters is "column volumes per unit time", so cutting the flow in half would double all the times, including regeneration/reequilibration.