The good news is that it will suck it dry - ONCE YOU GET IT STARTED. The bad news is you need to jig the valve end of the hose up and down quickly in about 5” of fluid AND have enough fluid to fill the hose to get it started. Great product for emptying large volumes of fluid (I use mine to put gas in my boat and to empty my hot tub) but, unless you are starting with a full tank with enough depth, it’s probably not the best choice for a small project.
The check valve, which gets immersed in the liquid being drained, i.e. the tank, could come off ! Also, the lash in the tube would make it difficult to prime.
Yes, you can add many more feet of length to the device, as long as the source that you are siphoning from is higher than the end of the new length of hose. The greater the difference in height, the greater the flow..., but within reason. There is a thing called "friction loss" that'll limit the length of your hose. Ask any firefighter that has gone to school. Happy dribbling!
No.Just make sure the tank you are filling is face due North. If you are pulling water from a lake uphill, just point the hose end to the North in the area you are filling. I have pulled water up 40 feet from one pond to fill a smaller pond. You may need to tie a horse shoe type magnet on the North end of the filling hose. Hope this is useful.