When using spiked hoods, the same standard values as for hood steaming are largely applicable.
The important difference is that more than double the quantity of steam per square metre comes under the hood due to the hollow spikes. This requires generation of a slightly higher surface pressure. Such pressure can, however, mostly be provided by the weight of the device itself. Furthermore, moving a spiked hood is a slightly more complicated process since you have to check that the hollow pins have smoothly penetrated into the soil when being lowered.
In this steaming system, you must ensure that the soil is sufficiently dry in order to keep the exit holes clean.
Moreover, the sandwich-type method is ideally suitable for steaming treatment of substrates and flow pots, which means you don’t have to empty and re-fill them.