So would you say a 150 micron mesh is not as efficient as a 150 micron felt

Technically they should be the same but the felt socks wear out much faster. Not always a bad thing but they let more through with each wash. The mesh socks seem to stay pretty tight.

How are they priced comparatively? Buying 5-6 socks of felt seem pricey.

sockless and liberated
 

Coincidental post. I am 3 days in of going sockless. With a new skimmer and ATO i thought it would be a great time to keep water levels consistent. First day was painful, but just like everything in this hobby, my patience has paid off. Water is getting clearer but I hope I don't **** off my sps. I have a simple open concept rubbermaid sump with no baffles or live rock etc. so it will be easy to clean. Time will tell but i'm excited about the reduction in maintenance i've achieved lately.

Biggest advantage is they are clean after washing them.

The felt socks never got perfectly clean.

I use the 7" felt and change them every couple days.
On our fish system we change them every day due to the heavy feedings.

My feeling is that they catch large particulate matter and allow me to remove it before it breaks down or accumulates in the sump.

I feel felt catches more that mesh, but it is definitely hard to get them clean.
We run ours threw the wash 3-4 times in a row and they never go back to 100 % clean but close enough as far as I am concerned. I used to wash them once, then turn them inside out and wash them again. I did find they got cleaner but they also seemed to wear out faster. Now I just wash them a few times in a row without inverting them.

Felt or mesh thats up to you but I would never run a system now without them.

Thanks

Same here not only it eliminates cloudy water, it helps get rid of water splashes and micro bubbles that goes into your display.

Where can you get mesh socks?