Wash hands and clean preparation area. Rinse all fresh ingredients under cool running water, then start chopping the red onion, green onions and slicing the watermelon radishes. Place chopped red onions into a medium bowl and place slice watermelon radishes into a large bowl.
Add lemon juice and sprinkle half the salt into the bowl of onions. Set aside.
Rinse the lid of canned goods under cool running water before opening. Open canned mandarin oranges and grapefruit. Before draining canned goods, reserve a tablespoon of juices from each container and pour them onto radishes. Set aside.
Then measure out the remaining ingredients, grapefruit, mandarin oranges, pecans, and olive oil, and add to the bowl of radishes.
Add the onions into the large bowl. Drizzle olive oil and sprinkle salt for taste. May place in refrigerate for about 10- 15 mins.