This guide will show you how to reduce lag on your Minecraft server by reducing your "View Distance" in 'server.properties' file.
What is View Distance?
View Distance sets the amount of world data the server sends the client, measured in chunks in each direction of the player (radius, not diameter). It determines the server-side viewing distance. The "Far" viewing distance is 16 chunks, sending 1089 total chunks (the number of chunks that the server will load can be seen in the debug screen - F3 in-game). "Normal" view distance is 8, for 289 chunks.
*10 is the default/recommended. If you have major lag, reduce this value*
How to reduce/change the View Distance?
In order to reduce/change your view distance, you will need to access your FTP (Details are in your TCAdmin Panel & Welcome Email), and find a file named 'server.properties', open it and look for "view-distance=10" (sometimes the number may be different depending on if you have edited it before, although 10 is the recommended and default), simply change it to a minimum of 3, the maximum is 15.