A good rule of thumb is to change 5% to 15% of your koi pon’s water every week. Partial water changes help keep your koi healthy, and replacing small amounts at a time prevents causing stress for the fish.

While they’re popular and have a lot of pros, the cons of river rocks include the following:

• River rocks don’t break down or provide nutrients to plants. 

• These stones can get hot and scorch nearby plants. 

• River stones may heat the surrounding soil to inhospitable temperatures. 

• Rocks can block rainwater from seeping into the ground if installations are too thick or tightly packed.

Most downsides occur when using river rock as mulch in gardens and flower beds. However, you can still incorporate river rocks into your landscape as long as you use them in the correct ways.

After you fill in your pool, you can add trees and plants that help stabilize the soil. You might decide not to fill it in at all and find another use for the sunken area instead. A few ideas include creating a seating area or garden inside the empty pool. Depending on its size, you could create a place to roller-skate or install basketball hoops for an unconventional court.

Most outdoor water fountains and features do not use a lot of electricity, typically consuming between 100 and 250 watts per day. The size of the fountain's motor can impact its overall electricity usage. To reduce energy consumption, you can use a timer to automatically turn the fountain off at night or when you are away from home. Additionally, installing solar power components can help lower electricity costs after the initial investment is recouped.