diff --git a/R/UnitConversions.R b/R/UnitConversions.R
index e0ce8d83..5b5127e0 100644
--- a/R/UnitConversions.R
+++ b/R/UnitConversions.R
@@ -638,20 +638,6 @@ TADA_ConvertResultUnits <- function(.data, ref = "tada", transform = TRUE) {
     # Remove unneccessary conversion columns
     convert.data <- convert.data %>%
       dplyr::select(-tidyselect::any_of(conversion.cols))
-
-
-    # Transform pH units to "STD UNITS"
-    if(any(convert.data$CharacteristicName == "pH")) {
-      print("TADA_ConvertResultUnits: harmonizing pH units to STD UNITS.")
-
-      convert.data <- convert.data %>%
-        dplyr::mutate(TADA.ResultMeasure.MeasureUnitCode = dplyr::case_when(
-          TADA.CharacteristicName == "PH" & TADA.ResultMeasure.MeasureUnitCode %in% NA ~ as.character("STD UNITS"),
-          TADA.CharacteristicName == "PH" & ResultMeasure.MeasureUnitCode %in% NA ~ as.character("STD UNITS"),
-          TADA.CharacteristicName == "PH" & ResultMeasure.MeasureUnitCode == "None" ~ as.character("STD UNITS"),
-          TADA.CharacteristicName == "PH" & ResultMeasure.MeasureUnitCode == "std units" ~ as.character("STD UNITS")
-        ))
-    }
     
     # Update ID and column ordering
     convert.data <- TADA_CreateComparableID(convert.data)
diff --git a/R/Utilities.R b/R/Utilities.R
index c30adc7c..fe11d895 100644
--- a/R/Utilities.R
+++ b/R/Utilities.R
@@ -340,7 +340,23 @@ TADA_AutoClean <- function(.data) {
   # Substitute updated characteristic name for deprecated names
   print("TADA_Autoclean: updating deprecated (i.e. retired) characteristic names.")
   .data <- TADA_SubstituteDeprecatedChars(.data)
-
+  
+  # Transform pH units to "STD UNITS" if "NONE" or "nu"
+  if(any(.data$TADA.CharacteristicName == "PH")) {
+    print("TADA_AutoClean: harmonizing pH units to STD UNITS.")
+    
+    .data <- .data %>%
+      dplyr::mutate(TADA.ResultMeasure.MeasureUnitCode = 
+                      ifelse(TADA.CharacteristicName == "PH" & 
+                               TADA.ResultMeasure.MeasureUnitCode == "NONE"
+                             | ResultMeasure.MeasureUnitCode == "None"
+                             | ResultMeasure.MeasureUnitCode == "nu"
+                             | is.na(ResultMeasure.MeasureUnitCode),
+                             "STD UNITS", TADA.ResultMeasure.MeasureUnitCode
+                      )
+      )
+  }
+  
   # Implement unit harmonization
   print("TADA_Autoclean: harmonizing result and depth units.")
   .data <- suppressWarnings(TADA_ConvertResultUnits(.data, transform = TRUE, ref = "tada"))
@@ -718,7 +734,16 @@ TADA_SubstituteDeprecatedChars <- function(.data) {
 #' @export
 #'
 TADA_CreateComparableID <- function(.data) {
-  TADA_CheckColumns(.data, expected_cols = c("TADA.CharacteristicName", "TADA.ResultSampleFractionText", "TADA.MethodSpeciationName", "TADA.ResultMeasure.MeasureUnitCode"))
+  
+  expected_cols <- c(
+    "TADA.CharacteristicName",
+    "TADA.ResultSampleFractionText",
+    "TADA.MethodSpeciationName",
+    "TADA.ResultMeasure.MeasureUnitCode"
+  )
+
+  TADA_CheckColumns(.data, expected_cols)
+  
   .data$TADA.ComparableDataIdentifier <- paste(.data$TADA.CharacteristicName, .data$TADA.ResultSampleFractionText, .data$TADA.MethodSpeciationName, .data$TADA.ResultMeasure.MeasureUnitCode, sep = "_")
   return(.data)
 }
diff --git a/data/Data_R5_TADAPackageDemo.rda b/data/Data_R5_TADAPackageDemo.rda
index 6e5b749c..1d66f852 100644
Binary files a/data/Data_R5_TADAPackageDemo.rda and b/data/Data_R5_TADAPackageDemo.rda differ
diff --git a/tests/testthat/test-Utilities.R b/tests/testthat/test-Utilities.R
index f2bbd3e0..ac6aec2c 100644
--- a/tests/testthat/test-Utilities.R
+++ b/tests/testthat/test-Utilities.R
@@ -8,28 +8,35 @@ test_that("TADA_AutoClean function does not grow dataset", {
   expect_true(dim(testautoclean1)[1] == dim(testautoclean2)[1])
 })
 
-test_that("TADA_AutoClean function harmonizes pH units", {
+test_that("TADA_AutoClean: pH harmonization works as expected", {
   
-  get_random_pH_data <- TADA_RandomTestingData(
-    choose_random_state = TRUE,
-    number_of_days = 5,
+  # get random pH data
+  random_data <- TADA_RandomTestingData(
+    choose_random_state = FALSE,
+    number_of_days = 1,
     autoclean = FALSE
   )
+  random_pH_data <- dplyr::filter(random_data, CharacteristicName %in% "pH")
   
-  pHtest <- dplyr::filter(get_random_pH_data, CharacteristicName %in% "pH")
-  
-  verify_random_data <- function() {
-    df <- pHtest()
-    while(nrow(df) < 200) {
-      df <- get_random_pH_data()
-    }
-    return(df)
+  while(nrow(random_pH_data) < 2) {
+    random_data <- TADA_RandomTestingData(
+      choose_random_state = FALSE,
+      number_of_days = 1,
+      autoclean = FALSE
+    )
+    random_pH_data <- dplyr::filter(random_data, CharacteristicName %in% "pH")
   }
   
-  pHtest2 <- TADA_AutoClean(pHtest)
-  
-  print(unique(pHtest2$TADA.ResultMeasure.MeasureUnitCode))
+  # TADA_AutoClean harmonizes pH, and other mod 1 required functions remove garbage data
+  pHtest <- TADA_AutoClean(random_data)
+  pHtest2 <- TADA_SimpleCensoredMethods(pHtest)
+  pHtest3 <- TADA_AutoFilter(pHtest2)
+  pHtest4 <- TADA_RunKeyFlagFunctions(pHtest3)
+  pHtest5 <- TADA_HarmonizeSynonyms(pHtest4)
   
-  expect_true(unique(pHtest2$TADA.ResultMeasure.MeasureUnitCode) == "STD UNITS")
+  # Is pH data harmonized after above mod 1 functions have run?
+  pHtest6 <- dplyr::filter(pHtest5, CharacteristicName %in% "pH")
+  print(unique(pHtest6$TADA.ResultMeasure.MeasureUnitCode))
+  expect_true(unique(pHtest6$TADA.ResultMeasure.MeasureUnitCode) == "STD UNITS")
   
 })