diff --git a/Software/MainBoard/rust/src/hal/water.rs b/Software/MainBoard/rust/src/hal/water.rs
index 2c3065e..bdbb3b7 100644
--- a/Software/MainBoard/rust/src/hal/water.rs
+++ b/Software/MainBoard/rust/src/hal/water.rs
@@ -2,7 +2,7 @@ use crate::bail;
 use crate::fat_error::FatError;
 use crate::hal::{ADC1, TANK_MULTI_SAMPLE};
 use embassy_time::Timer;
-use esp_hal::analog::adc::{Adc, AdcConfig, AdcPin, Attenuation};
+use esp_hal::analog::adc::{Adc, AdcCalLine, AdcConfig, AdcPin, Attenuation};
 use esp_hal::delay::Delay;
 use esp_hal::gpio::{Flex, Input, Output, OutputConfig, Pull};
 use esp_hal::pcnt::channel::CtrlMode::Keep;
@@ -17,7 +17,7 @@ pub struct TankSensor<'a> {
     one_wire_bus: OneWire<Flex<'a>>,
     tank_channel: Adc<'a, ADC1<'a>, Blocking>,
     tank_power: Output<'a>,
-    tank_pin: AdcPin<GPIO5<'a>, ADC1<'a>>,
+    tank_pin: AdcPin<GPIO5<'a>, ADC1<'a>, AdcCalLine<ADC1<'a>>>,
     flow_counter: Unit<'a, 1>,
 }
 
@@ -33,7 +33,7 @@ impl<'a> TankSensor<'a> {
         one_wire_pin.apply_output_config(&OutputConfig::default().with_pull(Pull::None));
 
         let mut adc1_config = AdcConfig::new();
-        let tank_pin = adc1_config.enable_pin(gpio5, Attenuation::_11dB);
+        let tank_pin = adc1_config.enable_pin_with_cal::<_, AdcCalLine<_>>(gpio5, Attenuation::_11dB);
         let tank_channel = Adc::new(adc1, adc1_config);
 
         let one_wire_bus = OneWire::new(one_wire_pin, false);
@@ -146,8 +146,7 @@ impl<'a> TankSensor<'a> {
         self.tank_power.set_low();
 
         store.sort();
-        //TODO probably wrong? check!
-        let median_mv = store[6] as f32 * 3300_f32 / 4096_f32;
-        Ok(median_mv)
+        let median_mv = store[TANK_MULTI_SAMPLE / 2] as f32;
+        Ok(median_mv/1000.0)
     }
 }