Rockwool clogging drains in flood table

Hi
I'm having some serious problems with my system. My trays are filled with Gold label hydrocorn and rockwool with the plants in.
I installed filters for my drainage made out of nylon socks, and after having the system running for a few minutes, the filters are completely clogged.
The stuff that clogs the filter really looks like its from the rockwool cubes, which I find weird since they should be safe for this kind of system.

Anyone experienced something similar? Should I get a less tight filter to let the particles through? Feels like it's going to clog up sooner or later anyway if I would.

Any help or ideas would be appreciated.

keep emptying it till all the particles are gone or get a bigger filter screen.

did you rinse the cubes before using them?how well?

maybe next time just fill pots with your medium. good luck