Occasionally newly installed pots will develop a white film or discolouration. It's a common thing that happens with pots containing terracotta or clay.
For many of our clients this is a natural characteristic of a pot, and they love it. Sometimes in modern balcony gardens, it can detract from a contemporary finish.
The reason leaching happens is because the moisture within the pot causes the natural salts in the terracotta to seep out through to the surface. This may also happen on our Balconylite Fibreglass ranges as they contain a mix of clay / terracotta to retain a natural finish.
In our experience, we find different batches of pots may have more salt than others - probably due to a slightly different mix.
Lower grade potting mix also makes a difference as colour within fillers in cheaper mixes can sometimes seep through. There may also be local environmental conditions.
We have found that the following course of action works: