Had to purchase hoses, by_pass and valves to attach pool heater. Need sunny location to place heater where there is no foot traffic. Must stop and start water flow to allow time for sun to heat water In heater. Pool size, number of heaters, amount of sun impact pool temperature… If placed on roof you may need a larger pump. I personally am unhappy with this purchase my garden hose laying in the sun produces hotter and more hot water in a day for the pool then the heater. Pool temp with heater, garden hoses and solar cover increased temp by 4*works greatWhat is the easiest way to send it back? It is not worth the money!Works perfectThe web site did not state we would need 3 additional paneles for my 16 ft above ground poolJunk. Had it less than a year and a seam split. With a 30 day warranty, I'm out 100 bucks. Don't waste your money. I have a small splash pool and this thing barely did anything. I live where we get well over 300 days of sun. It's just black plastic. Go to your local hardware and get pvc and heat absorbing black paint. Build your own and get far more volume.If I had not experienced it myself - I would not believe it could heat that much and that fast, I did install valves to control the flow but still flowing quite fast and can feel the hose temperature difference and increased my pool temperature 4 degrees in 4 hrs - mind you the sun heating pool too but still - I was skeptical when I ordered and am blown away - very very impressed and am going to save up and order a second, only issue that I have is to store for winter - will be a bit of work to take down and find a protected place to store.I have had two sets of those in the past. One set some 6 years ago, and one new since 2018. I have had issues with the first set because I left it outside during winter, but even with a complete drainage and winterization, there was always some leaks appearing every year that I had to repair - and that is not easy. In 2018, I purchased a new panel, that I have removed and stored it in a non freezable area (above 5C) during winter, and I have not had any leaks yet using it to warm the pool during the whole summer time. So, the recommendation is: STORE THE PANEL IN A NON FREEZABE AREA. Do not try to remove the water from it and leave it outside during winter - you will not win that battle !!Live on the west coast of BC where the average temperature on a hot day is between 20-30. Watched some Youtube videos, built a frame, bought a small pump, hung it on the roof, and ran some hoses. With 5 or 6 hours in the hot sun, the pool can rise 4 or 5 degrees easily. Whether or not it stands the test of time, I don't know yet.Attention !Ce n'est pas indiqué dans la description de l'article... Mais en lisant les instructions c'est écrit que c'est pour des piscine de max 15pi ... Et que pour une piscine de 15pi il en faudrait 2 comme ça.. et qu'avec un seul on gagne peut être 2 degré... Alors ça revient cher ! ...I was not 100% sold on this unit when I decided to buy it. However, I have to say that I am pleased with it. Unlike other units I have seen, this is very well made. The plastic welding is very uniform and professionally done. It's pretty durable.One bit of advice, when you receive it let it warm up in the sun so you can uncoil it with the minimum of stress to the plastic.I