As for hydroponics the correct PH of reserva tank or nutrient feed is the most important as this is your growing medium of choice being the water for such systems as DWC, NFT or inert growing medium suchs perlite or hydroton clay pebbles etc.
Any large swings in PH may cause nutrient lock outs etc leading to short term ill health of plants inless adjusted ASAP hence daily monitoring maybe required for such systems or intill the time your experience gains to leave em for an extra day or so before checking.