If you have the capability, best to QT anything wet for about a week.
Life cycle
There are four stages in the marine ich life cycle.
The feeding stage is known as trophont (or trophozoite). As the trophont feeds on tissue fluids, the distinctive white spot forms around the parasite as a cyst.
Once the trophont is mature, the cyst bursts and the free-living protomont emerges. Secondary infections can set in at this stage because of the damage caused to the host fish’s skin. Within a few hours the protomont settles onto a solid object, potentially even wet objects, such as nets, that can be moved between tanks.
Protomonts form capsules and begin dividing, eventually forming hundreds of infective cells known as theronts or tomites. In a tropical marine aquarium, this reproductive stage lasts for about three days.
After the reproductive phase is finished, the capsule bursts, and the theronts swim into the water and seek out new hosts. The theronts will die after a few days if they cannot find a suitable host.