Quite a lot of people use nylon thights (pantyhose) to built their own pre-filters. It's very cheap and the material is non-absorbant (Just check it's pure nylon)
I built filters for bumbelbee houses out of those, they work great. The only hassle is, you have to stretch them out as far as possible(!) / i.e. on a frame),
so the intake can suck enough water (in my case, so the air can circulate freely), otherwise their mesh/fabric would be too tight.
Other people prefer simple constructions with sponges as pre-filters (with fairly large pores), as those are much quicker to be cleaned compared to DIY nylon stocking
constructions ones.
I built filters for bumbelbee houses out of those, they work great. The only hassle is, you have to stretch them out as far as possible(!) / i.e. on a frame),
so the intake can suck enough water (in my case, so the air can circulate freely), otherwise their mesh/fabric would be too tight.
Other people prefer simple constructions with sponges as pre-filters (with fairly large pores), as those are much quicker to be cleaned compared to DIY nylon stocking
constructions ones.