We design and build ponds and waterfalls.That being said, A large part of our business is maintaining ponds.Some of the ponds we maintain were built by us, and some built by someone else. One thing is for certain. They all need maintenance. In nature things mature, and change with time, This goes for the man made ponds and waterfalls that we work on as well.Sometimes as things grow, they push something aside or even over power for its space or nutrients. Also sometime things in the pond just fall apart with age. The biggest maintenance issue is often sludge or bottom build up.All of these things are a normal occurrence in the life of a pond or waterfall, and easily taken care of with regular maintenance. You can do it yourself or call us We are happy to help. (858) 449-9135