I have a large map with only starting area water, and every time the sealevel updates, the game freezes for about a minute. You have it set to 5 minutes between each update, and I have a ton of pollution(1 rocket / 5 minutes with productivity 3's in everything you can imagine, areas with 50k polution). It might be a good idea to add a limit to how much it'll process each trigger. Not sure if its because of the pollution I have or the map size (27MB .zip), but it has some issues with it. When its not updating, everything runs fine (0.009ms used for the mod). No crashes so far either, so that's a major plus :)

On a side note, I love the idea of this, but you'll probably need to add some optimizations to it.

Welcome to Alpha. :3

The current method is to, most of the time, look for areas of water around the player. 20% of the time it will use a previously used area. If you have water only in the starting area and you have it completely surrounded with walls/pumps, then you should never see the water expand and this mod is wasting a lot of time looking for candidates it will never find.

Alright, updated to 0.6. It should perform a lot better now!