It's not a filtering issue. The sentiment is tren base without the ester. Tren acetate, as im told, is somewhat hard to manufactore. When you get this sediment, it's because during the production of the powder, not all of the tren base was able to bind with the acetate ester.
The recommendation I've found is to mix a small amount of tren enanthate in the brew, the free test base more easily combines with the enanthate ester. Sometimes this works, sometimes it doesn't. You could stand the vial in the same spot for a few days and let all the sediment drop to the bottom and only draw from the top. It won't make you sick or anything, but if you inject too much of the tren base sediment, you might get a wicked tren cough.
Anyway, this is a common problem with tren ace powder from China. It's not always perfect. Another common problem is PIP from Chinese test enanthate powder. That has something to do with some acid not washing out properly in the manufacture of the powder. If you get pain from enanthate, switch to cyp problem solved.