Hi Alex, Our sample rate is 16 kHz and our recording period is 00:00-24:00. It does not manage to write anything to the SD card.

Hi Alexa. We are using sandisk ultra 512 GB and energizer ultimate lithium batteries. This is the only hydromoth that we know of so far with this issue (we are going to pull another one later today to see if the same problem occurs). We leave the hydromoths out in the protective waterproof casing for a month at a time and have not had this issue before. No signs of corrosion however this morning the SD card port is giving us some trouble and not physically holding the cards we have tried in place, but it does recognize that an SD card is not there because it flashes red and green and when the SD card is in place no light turns on at all in default mode.