liquid horse poo

Hi.. I have had a fresh horse poo tea bag in my water butt for a week now and I am wondering what's ok to put it on and when.. I am growing, cabbage, courgette, runner beans, peas, potatoes, tomatoes, cucumber, aubergine, salad leaves, onions, garlic, peppers and loads of herbs, Plus flowers and shrubs in boarders...

Also I'm growing the potatoes in bags and I beleive I have to add more soil when I have shoots, but how long should the shoots be before adding it.

Many thanks