Dont waste ur time with 4” diameter socks… at the least run 7”x15”’s… i run those as well as 7”x32”… another “pro tip” is divide ur tank drains as many times as possible for more socks. The less flow through each sock the longer u can go between cleanings. Some of my setups go 6 months between changing… others can go well over a year. I run 200micron also. Found no difference in water clarity between 100 and 200 micron but the 200’s run longer between cleanings. If you try and put 1 tank drain into 1 sock at a high flow they will clog very quickly. I think this is were alot of people get turned away. When set up right with low flow they last a very long time before cleaning. 1 tank drain should be split into 2-4 socks IMO.