Even with the whatmans it takes FOREVER to filter through.
I just finished up brewing up about 170ml of 1-Test @ 176mg/ml and I had to filter that **** over the course of 2 days. I just sat in front of the tv both nights for hours. My hands got so tired it affected my deadlift grip strength the day after.
Oh, and for the record: Even at 176mg/ml it wasn't stable until AFTER it was filtered. I had to cook the unfiltered again the second night to get it back into solution. The filtered stayed in solution.
I haven't heard anybody talk about filtering being a factor in whether it stays in solution or not, but it does.