ideas for a small, simple diatom?

[Thever]

I have a 10 gallon tank and am using a eheim 2213 classic for a filter. I really dont see a justification to buy a diatom filter, but have seen some diy filters on the net. Any ideas on a small filter that could be put in front of the eheim? I have read about using a magnum micro filter and some powder, would that work?

Main reason I'm looking at this is a slight cloudy tank, and algae bloom I'm recovering from. Thanks for any input.

Kevin