The invention generally relates to positive-working coating compositions and to a substrate formed with a coating of that composition. In particular, the invention relates to a biodegradable polymeric water retention concentrate that when diluted and applied to various plant media improve water, fertilizer and nutrient retention in plant media with no root uptake or phyto-toxic effects. Advantageously, the apparatus provides universal support in a single structure for small containers up to large containers. The differential current integrating sense amplifier is also used for instrumentation, communication, data storage, sensing, biomedical device, and analog to digital conversion.