Add in or sprinkle on salad daily a multivitamin supplement and a calcium supplement. Store in a sealed food storage container. Stays fresh for 6-7 days. Additional quantities may be frozen. Add a tablespoon of brewer's yeast to the defrosted salad to replace the thiamin lost through the defrosting process.
Sunlight is critical for proper growth.
Be sure, however, to provide some shade. Being too hot is just as dangerous as being too cold. If regular direct sunlight cannot be provided for them, you must use UVB-producing fluorescent lights daily. Always have fresh water available for drinking. A large shallow bowl is best, one they can access but not accidentally tip into and possibly drown.