I have a low pop server running a 3500 sized map. Usually no more than 10 players on at once. Starting with the August update my RAM usage has gone way up, even causing me to get a message from my host and the server going down once. The host seems to think it may be one of the plugins I'm running. It's pretty much holding at a constant 6.5-7.5 GB of usage even with no players on. I tried unloading each plugin one at a time and didn't see much of a difference. 

Any ideas on what I can do to lower the usage? Should I just upgrade the RAM?

Current entity count is 62207

Plugins:

01 "Active Sort" (1.0.4) by Egor Blagov (0.62s) - ActiveSort.cs

02 "AdminHammer" (1.13.0) by mvrb (0.00s) - AdminHammer.cs

03 "Admin Radar" (5.1.4) by nivex (28.99s) - AdminRadar.cs

04 "Better Chat" (5.2.7) by LaserHydra (0.08s) - BetterChat.cs

05 "BetterLoot" (3.5.3) by Default (20.27s) - BetterLoot.cs

06 "BotSpawn" (2.1.9) by Steenamaroo (185.76s) - BotSpawn.cs

07 "Bradley Guards" (1.3.6) by Bazz3l (0.89s) - BradleyGuards.cs

08 "Gathering Manager" (2.2.75) by Mughisi (0.40s) - GatherManager.cs

09 "Join Message Plus" (1.0.54) by MisterPixie (0.08s) - JoinMessagePlus.cs

10 "Lights On" (1.6.18) by mspeedie (22.05s) - LightsOn.cs

11 "No Give Notices" (0.3.0) by Wulf (0.01s) - NoGiveNotices.cs

12 "PlayerList" (0.3.2) by Wulf/lukespragg (0.01s) - PlayerList.cs

13 "Quick Smelt" (5.1.3) by Iv Misticos (1.10s) - QuickSmelt.cs

14 "SkinBox" (2.0.8) by k1lly0u (6.97s) - SkinBox.cs

15 "Stack Size Controller" (3.4.3) by AnExiledGod (5.27s) - StackSizeController.cs

16 "Vanish" (1.5.5) by Whispers88 (0.27s) - Vanish.cs

17 MapProtection - Unloaded

I am having the same problem, I am also running a low pop server (sad to say) using a 4500 procedural map , BUT have 90 plugins running,
I use entity reducer plugin which does cut down the entities,
I start the wipe with about 5700 entities with no bases built, this will slowly creep up day by day by about 3000 enitities until i get to about 300.000+  by the end of the wipe and using 90%+  of the 16gb ram, I restart the server once a day to clear it a bit,
i upgraded to 16gb ram three wipes ago when i saw the increase in entities which is when i loaded Entity Reducer plugin to try and get them down, i have also reduced loot in various areas of the map especially floating and sunken loot ,
it is very annoying that this game has demanded more and more ram with a sometimes huge  increase in entities for no apparent reason,