# Choosing filter paper



## Rreyes097 (Sep 14, 2021)

What is everyone go with for filter paper what are the numbers and specs mean and what sizes do people normally use I'm just trying to get a feel for it before I buy those round ones I've been using coffee filters but I'm trying to get the other kind now.


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## Probrefiner (Sep 15, 2021)

Hi

I used to use Whatman quantitative 540 - 542 filter papers for most precipitates in acid and base solutions very consistent with good retention, I think it depends on what your looking to filter?

Regards 

Rob


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## Martijn (Sep 18, 2021)

I use these. 


I rarely use the flat round ones.

Editet for spelling.


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## goldscraphobby (Sep 20, 2021)

I have been using coffee/tea filters for filtering first then going to whatman round ones for the fine filtering with a Buckner funnel. I had been having issue with stuff getting under them so I recently tried the "charmin plug" using using a funnel & fiberglass. I took a wide mouth funnel and stuffed fiberglass into it.

This thing was fantastic, very fast filtering and very clean solution. I'm not going back to the other way.
A lot cheaper to run. 
I also now do a pre-filter to skip the coffee filter. I stuff the funnel with a large piece of fiberglass and then put another small piece of fiberglass at the top (the pre-filter).

I just remove the "pre-filter" to get rid of the large crap and for the next filtering I add another pre-filter.


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