It is wise to experiment to get just the right soil mixture to fit the wick that you are using. Generally the farther, or higher, your plant is from the water source, the finer your soil mixture should be. The finer the soil, the greater the pull on the water. However, if your plant is just above the water, a medium-textured soil will be adequate. Again, make sure your plants are well established with this system before leaving on a holiday.
Many people place their plants in the bath tub before leaving for vacation.
This is an effective approach. Water the plants well and cover them with a sheet of plastic. They will survive on their own in the tub for 2 weeks or longer. Water the plants well and cover them with plastic. In the Bag A plant can survive for some time without watering if it is placed in a clear plastic bag.