Be careful when mixing varieties, as all breeds do not get along. Finches are social birds and prefer to be kept in a colony setting. If breeding is not desired, females can be kept together without difficulty. Finches also require the ability to nest and do best with covered nesting. Finches should eat a staple diet of fresh fortified finch seed or pellet daily.
Finches only eat off the top of what is offered, so be sure to check the food daily.
Besides a variety of seed mix or pellet, offer chopped dark green and yellow vegetables and a variety of fresh fruits in addition to a protein source like mature legumes, hard cooked chopped egg, and grated cheese. Remove fresh fruits and vegetables within 2 hours of offering to prevent spoilage. If the bird gets too much liquid from the fresh fruits and vegetables, the droppings could become runny. Stop the fresh food for a day to see if this is the reason. Millet Spray also makes an excellent supplement for finches.