Merfolk- Standard

looks good but i wold suggest taking out the cumbering stone- it costs too much for not much, its basically a fourth turn lost where you could be building up your game, i would also consider getting rid of rest for the weary and call to mind. rest for the weary at the end of the day is just a stall card when not in a life gain deck, i would try to find something that works the deck better, though of course in some situations it may help. Call to mind seems like a wasted space for something else as well. if you were using it for rest for the weary, why not just max those out? or if you were using it on the counters, it seems almost counterproductive (excuse the pun) because now your opponent knows what you are holding and will probably hold his trump card until you are tapped out or use it against something less threatening. as to what cards to throw in, maybe some spreading seas- it gives you a draw mechanic and helps so mana screw your oppenent as well as give your seastalkers their islandwalk (maybe a good sideboard card). i would also replace crystalization for journey to nowhere or paths. also, sideboards are 15 cards so you need to trim one off. other than those ideas, it still looks like a pretty solid build, nothing wrong with it, it just may have some room for improvement. hope it goes well at FNM.