I just finished my current batch of plants, I'm gonna start getting my new one today, so I'll test it thoroughly, hopefully finding the problem...
I'm also working on the new version, which is A LOT faster....
Version 0.5.2 takes me 1h30 min to tend for 1500 plants...
This new version took me 58 minutes...

If you have lower ping, and use cacti, I guess this time could be even shorter...
I'll try and get that version up later today...
Thanks for the input Cerveza...