Re: Is the salt and sand on seaweed an issue? No there are four hundred trace elements in sea water. A little salt is OK In fact plants in the Brassica (cabbage etc) family seem to respond well to it. I have just collected a bag of weed from my local lake (I refuse to buy seaweed fertiliser -It is the same price as red wine!) The local Land-Care Group sometimes bags some up for the lazy. There is so much of it. It is chocking the lake. With Draconian Water restrictions it makes a great mulch. I am composting it at the moment as I find it hard on suburban plot to get enough organic matter to keep a compost pile going. I am also using a handful of it in the bottom of pots of mint. They love it!