The problem is, get rid of the aphids and the ants bring more. They seem to have an inexhaustible supply.
Spray the plant with rubbing alcohol cut about a half or so. It kills aphids on contact.
Also, get a little dish, put some jelly in it, and pour borax powder around the jelly, then put it by the plant. The ants take the borax back to the nest and die. Or, put the plants or their stands in trays full of water so the ants can't get to the plants. Depending on time of year, etc., empty the dishes every couple of days to keep mosquitoes from hatching.