tomato feed should be ok for your chilli plants

If you are tight fisted like me and want to save money, cut down a whole clump of nettles from somewhere, chop them roughly into pieces and soak them in a large bucket or container for about a month, and strain off the result. Dilute the resulting foul smelling 'brew' with water in your can to the colour of weak tea, and use the result as your feed.
Better than the best proprietary tomato feed and good for chillis.
You can use comfrey instead of nettles without getting stung, but nettles are usually easier to find.