Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to use solar energy to heat a pool [title] Use a long, dark-colored hose to fill up your pool. [step] The longer it takes for water to make its way through the hose and into your pool, the warmer that water will be. While fifty feet of hose is generally sufficient, additional length means the water will have even more time to warm up.

Ending1: When it is hot enough, the water will then be absorbed and you can make even larger pools with one section of the hose. [title] Splice your hose into a tight, hot and humid location. Ending2: [substeps] If your pool is very cold, be sure to use a thick water cap or a thick rubber hat when covering it with a hose. [title] Set a timer on your gas meter. Ending3: The added surface area of the hose collects more heat, as well. If you use a dark-colored hose, the water can get even warmer because dark colors absorb more solar energy. Ending4: [title] Remove any debris from the river or river or river during the installation process. [step] This can include gravel, grass, rocks, etc.

Answer format: ending1/ending2/ending3/ending4