I've run out of my regular plant food and can't get any more for a few days, what should I do?

Do not just give your plants plain water, as this would be a terrible shock to the plant- not to mention you would be starving your plant if even for only a few days. Buy an all-purpose water soluble plant food at your local garden center. If you can, measure the EC or ppm after mixing the solution, to make sure you are giving the same level of plant food as before. Your plants should continue to grow, until you can buy your regular plant food.