diff --git a/tree-water-demand/src/main/java/de/hft/stuttgart/water/TreeWaterDemand.java b/tree-water-demand/src/main/java/de/hft/stuttgart/water/TreeWaterDemand.java
index 71c354778cd1ab86f8e782e9bca312b2212bf074..9798d78316f0dfded3b60bb68094c24b9dc68ac7 100644
--- a/tree-water-demand/src/main/java/de/hft/stuttgart/water/TreeWaterDemand.java
+++ b/tree-water-demand/src/main/java/de/hft/stuttgart/water/TreeWaterDemand.java
@@ -101,14 +101,10 @@ public class TreeWaterDemand {
 				int dayOfYear = counter.getDayOfYear();
 				double hourOfDay = counter.getHour() + 0.5;
 
-				//TODO: DRY
-				double netRadiation = rn(temp, actualVaporPressure, incomingRadiation, height, dayOfYear, hourOfDay,
-				lz, lm);
-
-				double extraterrestrialRadiation = extraterrestrialRadiation(dayOfYear, hourOfDay, lz, lm);
-				double netLongwaveRadiation = rnl(temp, actualVaporPressure, incomingRadiation, height, dayOfYear, hourOfDay, lz, lm);
-				double et0 = et0(temp, actualVaporPressure, incomingRadiation, height, windSpeed, humidity, dayOfYear,
-						hourOfDay, lz, lm);
+				double extraterrestrialRadiation = extraterrestrialRadiation(dayOfYear, hourOfDay, lz, lm); // ra
+				double netLongwaveRadiation = rnl(temp, actualVaporPressure, incomingRadiation, height, extraterrestrialRadiation); // rnl
+				double netRadiation = rn(incomingRadiation, netLongwaveRadiation);
+				double et0 = et0(temp, actualVaporPressure, incomingRadiation, height, windSpeed, humidity, netRadiation);
 				double et0u = et0u(svf, advection, et0);
 
 
@@ -163,9 +159,7 @@ public class TreeWaterDemand {
 	}
 
 	private static double et0(double temperature, double actualVaporPressure, double shortWaveRadiation, double height,
-			double windSpeed, double humidity, int dayOfYear, double hourOfDay, double lz, double lm) {
-		double netRadiation = rn(temperature, actualVaporPressure, shortWaveRadiation, height, dayOfYear, hourOfDay,
-				lz, lm);
+			double windSpeed, double humidity, double netRadiation) {
 		double gamma = gamma(height);
 		double saturationVaporPressure = saturationVaporPressure(temperature);
 		double delta = delta(temperature, saturationVaporPressure);
@@ -197,21 +191,18 @@ public class TreeWaterDemand {
 	}
 
 	// unit is apparently [MJ / (m².h)]
-	private static double rn(double temperature, double actualVaporPressure, double shortWaveRadiation, double height,
-			int dayOfYear, double hourOfDay, double lz, double lm) {
+	private static double rn(double shortWaveRadiation, double rnl) {
 		// 1 - 0.23: albedo effect of grass
-		return (1 - 0.23) * shortWaveRadiation
-				- rnl(temperature, actualVaporPressure, shortWaveRadiation, height, dayOfYear, hourOfDay, lz, lm);
+		return (1 - 0.23) * shortWaveRadiation - rnl;
 	}
 
 	// unit is apparently [MJ / (m².h)]
 	private static double rnl(double temperature, double actualVaporPressure, double shortWaveRadiation, double height,
-			int dayOfYear, double hourOfDay, double lz, double lm) {
+			double extraterrestrialRadiation){
 		// divide by 24 for hourly
 		double sigma = 4.903E-9 / 24;
 		double rs = shortWaveRadiation;
-		double ra = extraterrestrialRadiation(dayOfYear, hourOfDay, lz, lm);
-		double rso = (0.75 + 2 * 10E-5 * height) * ra;
+		double rso = (0.75 + 2 * 10E-5 * height) * extraterrestrialRadiation;
 		double rsRsoQuotient = 0.5;
 		if (rso != 0) {
 			rsRsoQuotient = rs / rso;