And here is the alternative view:
No, you shouldn't run them unless you've a special situation that warrants it (such as a precipitated calcium carbonate "snowstorm"), and then only briefly.
There are a few reasons for this alternative view:
You don't need any additional light penetration, nor crystal clear water. Reef tank lighting has evolved to the point where too much light is the more common problem. If you're a diver, you know that water isn't crystal clear on very many real-life reefs, and it certainly isn't all the time even on ones that occasionally are crystal clear with 300 visibility in the a.m. That same reef after dark will be so cloudy with phytoplankton and zooplankton that you'll be lucky to have 10 foot visibility.
Which brings up the main reason not to run filter socks. They do remove some things that you might not want in your system, or at least a lot of in your system, but they also indiscriminately remove things you do want in your system, such as copepods and amphipods. Even when you're talking detritus, it makes a heck of a lot more sense to occasionally vacuum out the bottom of your sump where it's accumulated and pull out far fewer living parts of your mini-ecosystem. And removing the detritus but not using filter socks allows many other creatures an opportunity to find leftover fish food rather than it being immediately removed by a sock.
Good points - but I'll counter:
A comparison between a real reef and a reef tank is not a fair one, for the following reasons (and probably a whole bunch more) -
1) A real reef is lit by the sun, which has PAR and PUR values far exceeding anything we can possibly duplicate with artificial lighting over an aquarium;
2) A real reef has a flow / water exchange rate / dilution volume which far surpasses the capacities of even the largest commercial public aquariums - never mind a home reef tank;
3) A real reef has a diversity of organisms (especially non - photosynthetic and microbial / planktonic) which - again - we can not hope to even come close to under artificial conditions.
Due to the above 3 items, a real reef has the capacity to absorb and negate fluctuations in things like detritus output to a magnitude that is impossible under home conditions. In a closed artificial environment, the aquarist needs to take addtional measures not needed in nature (i.e. no one had to vaccum out the sandbed, or do a water change on the ocean)
IMO the amount of 'good' things (pods and the like) removed via a filter sock is negligible compared to the amount of potentially 'bad' things (such as detritus, uneaten foods, waste products, etc) that are removed. And, again IMO, the overwhelming majority of hobbyists do not undertake proper huisbandry measures - such as vacuuming out detritus accumulations in the sump - with sufficient frequency as to make them effective.
Look at it this way -
We have people griping that changing out a sock every day or 2 is 'too much hassle'... but getting a bucket and some vinyl tubing and getting down on your hands and knees to siphon out detritus from your sump, maybe moving around any live rock / live sand / macroalgae you have down there... and then replacing the water you removed... is certainly more 'hassle' than switching out a sock, isn't it? So how often is the vacuuming gonna get done, really?
And if we are saying one of the main 'drawbacks' to running socks is that they need to be switched out every day or 2 to avoid breakdown of all the stuff that gets trapped in the sock... and you DON'T run a sock... so all that crap ends up in your sump...
Well, are you vacuuming that sump every day or 2? Because that same detritus 'breakdown' you were just worried about inside a dirty sock is still gonna happen inside that dirty sump.
If you can tell me that you vacuum out the accumulated detritus from syour sump every few days - religiously - then by all means, ditch the socks...
But I have only met 1 person in my 35+ years of doing saltwater that was anal / crazy enough to actually keep to that kind of cleaning schedule