function doBalanceFor(address a) {
		bool found=false;
		for(var i=0;i<members.length;i++) {
			if(members[i]==a) found=true; 
		}
		if(!found) throw;
		
		GridMember g = GridMember(a);
		actual_feedin+=g.actual_feedin();
		actual_feedout+=g.actual_feedout();
		

		g.sendToAggregation(g.actual_feedin()+g.actual_feedout());
		lastbalancing[a]=now;
		
	}