diff --git a/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
index 01bc8e9..abb18a3 100644
--- a/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
+++ b/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
@@ -51,6 +51,7 @@ private void insertMetric(Jedis jedis, long siteId, double value, MetricUnit uni
         String metricKey = RedisSchema.getDayMetricKey(siteId, unit, dateTime);
         Integer minuteOfDay = getMinuteOfDay(dateTime);
         jedis.zadd(metricKey, minuteOfDay, new MeasurementMinute(value, minuteOfDay).toString());
+        jedis.expire(metricKey, METRIC_EXPIRATION_SECONDS);
     }
 
     /**
diff --git a/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
index 1da030f..4ea8671 100644
--- a/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
+++ b/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
@@ -47,7 +47,7 @@ public void update(MeterReading reading) {
             ZonedDateTime day = reading.getDateTime();
             String key = RedisSchema.getSiteStatsKey(siteId, day);
 
-            updateBasic(jedis, key, reading);
+            updateOptimized(jedis, key, reading);
         }
     }
 
@@ -80,8 +80,19 @@ private void updateBasic(Jedis jedis, String key, MeterReading reading) {
 
     // Challenge #3
     private void updateOptimized(Jedis jedis, String key, MeterReading reading) {
-        // START Challenge #3
-        // END Challenge #3
+        String reportingTime = ZonedDateTime.now(ZoneOffset.UTC).toString();
+        try(Transaction transaction = jedis.multi()) {
+            transaction.hset(key, SiteStats.reportingTimeField, reportingTime);
+            transaction.hincrBy(key, SiteStats.countField, 1);
+            transaction.expire(key, weekSeconds);
+
+            compareAndUpdateScript.updateIfGreater(transaction, key, SiteStats.maxWhField, reading.getWhGenerated());
+            compareAndUpdateScript.updateIfLess(transaction, key, SiteStats.minWhField, reading.getWhGenerated());
+            compareAndUpdateScript.updateIfGreater(transaction, key, SiteStats.maxCapacityField, getCurrentCapacity(reading));
+
+            transaction.exec();
+        }
+
     }
 
     private Double getCurrentCapacity(MeterReading reading) {