Pachiras

[Nick62lr]

Hi, I've just bought a beautiful Pachira plant which is about 5 foot tall. It has been on the conservatory for about 3 weeks and has been doing fine up until now. I have just noticed some small white/brown patches appearing on some of the leaves. Any ideas as to what might be causing this - are there any known bugs that effect the Pachira or will it be more due to light/watering? It is still in its original pot and I have thoroughly watered it (but not over watered it) and am letting the soil dry out between waters. It is next to a window where it gets some sun between 1 and 4. The temperature in the conservatory ranges at this time of year from 25 to 15 degrees. Also whilst I think about it will it be OK to leave it out there all winter? The conservatory is heated but the temp will drop to 12 deg some nights in mid winter.