Fishmom is right! I water my deck planters with leftover orchid water. The same planters in front of the garage get time release and water, period. The ones in back are much nicer, as are my patio tomatoes.
If you don't have a lot of orchids, you can filter your tap water in a filter pitcher. Our well is deep so the TDS isn't bad but, it has a lot of iron, the filter helps.