Soil acidity/alkalinity

Soil pH should be 6.5” – Chile Pepper Institute

pH is a scale used to measure acidity or alkalinity. The scale goes from 1 to 14 with a reading of 7 indicating a neutral balance, neither being acid nor alkaline. A pH of 6.5 is just slightly on the acidic side of the scale.

This is one of those recommendations for “optimal” results. As noted in other posts, capsicum plants will grow in a variety of soils, so no point worrying excessively.