Growing conditions: Greenhouse, soilless.
Growing medium: scoria, crushed to about ¼ inch diameter, or pumice of a similar size to be an ideal growing medium.
Water time obviously varies from day to day and season to season, according to the plant's needs. It should be noted that, in order to keep salts to a level which delphinium will tolerate (relatively low) it is necessary to flush the plants with water for about half an hour at least once a week.
The recipe is for fertilizers to be mixed into a 20,000 liter tank and watered out as is. No dilution is required. Fertigation being applied until the trays in which the delphinium plants were growing were saturated, and water began to seep out of the drain holes in the trays.