Don't forget to wash the salt off or collect it after a heavy rain storm
Bad Penny - Kelp would be better for composting as it has more dynamic accumulators, see below:
Name Na I Fl B Si S N Mg Ca K P Mn Fe Cu Co Kelp x x x x x x Bladder wrack x x x You could also make your own liquid seaweed feed (like Maxicrop) - get a 10 gallon container, half fill it with seaweed and top up with water. Let it brew for 3 months and then it's ready. Make sure you dilute it (about 10ml to 1 litre of water) as it's quite strong.