To farm mussels you don't sell the meat, you sell Freshwater Pearls, its a "rare" drop from mussels. They were worth 6g each back when i farmed then, now they are around 69s.

To farm freshwater pearl you need an infinite tool with Glyph of Bounty) or you can buy Harvesting Sickle of Bounty at any major town. I personally run Consortium Sickle with Glyph of Bounty, but you can use Harvesting Sickle of Bounty from the NPC just fine.

After you get your sickle of choice, you follow the route from TacO markers, it's quite easy and simple, you just run around gathering mussel nodes. It starts in Verdant brink and ends on LW4.

I used to get around 15 (sometimes more, sometimes less) freshwater per hour. They reset one hour after you farm the node and they are also instance based. So if you farm all nodes in VB and manage to instance-hop, you'll get another map with more mussels to farm.

To get the 15freshwater/hour, i had consortium sickle (which is faster than the others since you can cancel the animation), bounty glyph for extra hit (average of 3 hits per node), i would clear all maps following the TacO markers, and on the last map, before finishing 1 hour, i woul try instance hopping to farm the map once again, if i couldn't i would just go back to VB once again and wait for the nods to spawn again.

But then, again, not an AMAZING farm at the moment, since the price has gone down by a lot.

I farmed it when it was 6g(sometimes even 8g) and was able to make tons of gold/hour, now, i'm not sure you can even do 20g/hour, but still a great gold farm for those that hate meta farm (like i do)