The temperatures are getting a little warmer and the pond water has been looking darker (and stinkier).  While the pond could really use a through cleaning, it’s still not that warm in Minnesota.  We drained a great deal of the water and pulled out a number of rocks. It wasn’t the most thorough cleaning, but it should make it a little easier when we tackle the sludge again in a few weeks. At the koi club meeting, we heard a lot of pros and cons about rocks in the pond, mostly cons.  Removing a number of the rocks certainly freed up some swimming space for the koi and the pond looks a little healthier.