Cactuses from Holland: transplanting
There is always a question about transplanting. Here are two variants: to keep an old soil or transplant, deleting it completely. Each of them has pluses and minuses.
First of all, having got a plant from a pot, you should examine roots very attentively and if necessary to cut off damaged or diseased. Examine soil for centers of plant pests. And only then begin transplanting.
If you have decided just to plant in a bigger pot without removing old soil, then just add some soil. Plus of this variant is that the plant should not spend forces for settling in an unfamiliar soil, and it is easier to adapt. A minus is that the old soil can hide pests. Besides the difference in structure of primary and added soils can negatively influence growth of a plant because of an uneven moisture capacity. This Dutch peat dries up and injures roots.
If you are going to transplant your cactus, then you should remove a store peat soil completely. The easiest way is to soak and flush root system under a jet of warm water. Having dried a cactus within 1-2 days, it is planted in a dry soil. Plus of this variant is that there can not be any pests and your cactus is put in a good soil. And a minus is that the plant will need time to adapt to new soil after such washing and to restore damaged roots. Sometimes cactuses cannot simply get used to such sharp change of soil conditions, do not grow new roots and perish.