I asked a question and for some reason could not find any place to receive the answer. So, here I will try again. Can I use water out of the Columbia River or not? What happens when it rains here and the pitcher plants fill with water up to the top of the plant? I was told on our visit to the nursery 2 weeks ago that the water level should only be up half way. I am spending a fortune on distilled water and need to know the answer to my questions ASAP.
Letís tackle the quality issue first. Carnivorous plants are sensitive to minerals in the water. Contrary to popular belief, the chlorine in city water isnít that big of an issue to them, itís all the other stuff in hard water, calcium, magnesium etc... Vancouver gets itís water from wells, so it has a high mineral content rendering it unsuitable for long-term use with carnivores. Water from the Columbia river is going to be very hard also, since it has hundreds of tributaries all dumping their minerals in the water. Water from a small stream or creek in coming from a forest would be very different. They tend to be very low in minerals West of the Cascades.
Until we get back to the rainy season, the most cost effective thing to do would be to get some 5 gallon jugs and go down to Portland to get water. The Bull Run water supply in Portland or Gresham is very low in minerals. Once we get the rain coming back, rainwater is great. Since you have a larger collection of plants it might be worth considering a small reverse osmosis filter for summer. Many different kinds are on the market, and a web search will give you lots of them. If you would like help with this let us know. Here's an example of one: https://www.amazon.com/Hydrologic-HYDROLOGIC-31026-Hydro-Logic-Compact-Portable/dp/B016N6DBZK/ref=sr_1_1?ie=UTF8&qid=1470763134&sr=8-1&keywords=hydrologic+reverse+osmosis+micro+75
Water depth. If you still have your plants in the pots that they came in from us, they should be sitting in shallow water trays. Itís true that the water should be no more than half way up the pots deep. Once the rains begin again, the simplest thing to do is make sure whatever tray they are in is shallow enough so that it doesnít flood the pots. If youíve transplanted the plants into different containers, they should have drain holes in the bottom and a water tray to sit in, or just be big enough so that the soil media holds significant water such as our bathtub garden in the nursery you saw. The plants should not be in non-draining planters since you will get anoxic conditions and bacterial build up. This is true for all plants, not just carnivores.
Pitcher plants filling with water. If you're talking about plants such as Sarracenia rosea, Sarracenia purpurea and hybrids that have open pitchers (as opposed to lids like many of the trumpet varieties of Sarracenia) it is normal for them to fill with water. Water will eventually spill out of the pitcher just as it does in nature.