I'm going to be hooking up an LG refrigerator soon, model LFXC22526S. Anyone have experience with this model or one with same/similar configuration? I don't know the length I'll need for the 1/4" x 1/4" compression supply line. One place says 5' and another says 10'.

Hello, I am doing a complete reno of our master bathroom. This started because i noticed water damage on the wall directly below the master bath toilet. Once the toilet was removed it was clear that it had been leaking for some time. The subfloor and flange both need replacing and the wax seal was in terrible shape. I took this opportunity to redo the whole bathroom which was in desperate need of it. The master bath toilet is back to back with the toilet in the main upstairs bath. Previously i noticed that when one toilet was flushed the water in the opposite bowl would move. Now that the master toilet has been removed I notice the rag that I stuck in the pipe look to be pushed out from the pressure when other toilet is flushed. The rag is also always damp and I have even seen a little water be "pushed" past the rag and onto the subfloor when the toilet is flushed. With a terrible flange and seal it appears I found the source of the water. Now here is my question. After doing some research it appears that this may be due to the toilets utilizing a double sanitary tee (which i can just barely see in the wall/floor). The increased velocity of modern toilets forces the water into the other toilet's pipes. According to the "online gurus" the solution is to change it to a double combination wye. Now this would be pretty intense job due to its location and that it is in-between the first and second floor. If I were to replace the subfloor, flange, and seal to ensure a good connection, would this be enough to prevent the water coming back out of the pipe when the opposite toilet is flushed? I don't mind the water moving in the bowl, and the water level remains the same when the other toilet is flush, so I am not concerned about that. I just don't want the water to leak again and ruin the floor. Side note: Before the masterbath toilet was removed I have never noticed any issues of water leaking in the main bathroom when the master bath toilet was flushed.