When high/low temperature is triggered, the current temperature will flash until it is lower/higher t than the set value. Clean dry the outside glass of the aquarium. Press and hold the “set” key, the first small number will flash, short press “up” or “down” to set up the highest temperature you want it to flash, then press “set”, the other small number will flash, short press “up” or “down” key to set up the lowest temperature.
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