I would not leave the water in the rock and then encase it in concrete. You need to get the water out somehow. The suggestions about pipe are good. I have also installed these lifts. Make sure you pour the concrete to the correct spot on the lip of the tube. There should be a sticker on the top...
I use a Bose docking station for my I-phone, I-pod. No wires to run , no speakers to hang and it takes up very little room on a shelf. I bought the rechargable one so I can move it to the wood shed or the deck or wherever. If you have wireless internet you can listen to radio or music from all...
Try reading glasses and when you still can't see shine a flashlight on what you are trying to read. Makes all the difference to this 60 year old. i have to do this to read numbers on blocks, tire sidewalls, just about anything that is not in bright sunlight.