Which whatman?

[Supermanjw84]

Which filter is better whatman .45um or .2um on unfiltered oil?

[ODB]

A lot of guys stick with the .45um filters.
Ffor a very long time the .45um filters were the gold standard in filtering until it was discovered that they did not filter out "Brevundimonas diminuta" and smaller than .45um organism.
That's when the standard changed to .25(.2)um filters even tho there have since been discovered organisms that are smaller yet.

[Supermanjw84]

One filter should filter how many mls? Sorry new to this.

[colochine]

One filter should filter how many mls? Sorry new to this.

3 times the quantity of the filter. If you get a bottle top filter that is 250ml you can filter 750 through it before integrity is lost.

[ErikGearhead]

.2 is the only thing I would recommend using. .45 puts you at risk for smaller organisms getting into your brew.
I'd suggest the nalgene rapid flow bottle-top filters, they work very well and very fast compared to the whatmans

[delcapone]

Ive read .22 is the way to go. Also that you can get 100mls out of a syringe filter.