Welcome Nigel,
You will need to quantify how much coolant is being used in how many miles.
Probably stating the obvious, but top up to the max mark when cold, note mileage, check daily, and say top up again after one week - or less if loss is substantial.
Can you see any evidence of pink coolant deposits anywhere, any evidence of drips on driveway, any signs of water emulsion in the oil?
Kind regards,
Gareth.