When calculating tube cost, you need to factor in the life expectancy of the tube. Tubes are available in several heights ranging from 18 to 36 inches. One advantage to using a tube over 24 inches is a reduction in labor required for vine training. A tube height of 30 to 36 inches is probably best for most applications. Lateral-shoot growth is suppressed while the main shoot grows quickly in the tube.
Vine training is required after the shoot tip exits the grow tube and lateral-shoot growth begins.
Internode lengths are often longer in the portion of the trunk covered by the tube due to rapid growth. This can result in fewer water sprouts in subsequent years and a further reduction in labor. Tube diameter is critical for the production of strong vines with thick trunks and large root systems. This is one of the best grow tubes available and was developed after years of research using different pigments, dyes and filters. Vines grown in milk cartons grew for 139 days before reaching topping height.