After yet more reading up on what makes a chilli plant happy. I noted that as they normally frequent hot countries they like humid environments.

To achieve this there are a number of recommendations:

1. Only water the plants with luke warm tap water.

2. Add stones to the saucer the plant pot is standing in. In this way water can be left in the saucer so it will evaporate creating humidity. Without the stones the water would be absorbed into the soil and the roots could drown.

We don’t have any spare saucers (that I would be allowed to use), and all the plant pots had holes in the bottom.  No option but to amend the pot I was already using for standing the current pots in.

Then armed with two orange milk carton tops and general household sealant I created two bungs. The pot was then filled with a layer of stones and just covering the carton tops. Water was added and after confirming no leaks in went the chilli plants.

Success!

The next project has got to be adding lights so I can monitor my plants in the evening.