I've been trying to get that nipple (right side) into the hose but it only goes in about 1/2". Would it be easier if I was to heat the hose up, wet it, or something else?
Oh, that's going to be tough. Hot water helps soften the hose up, but that hose isn't going to make it any easier (not very rigid). My best advice, use the hot water to soften the end and use your man muscle to ram the hose onto the barb.
Tried the hot water thing and it was still hard as hell to get on. But i did figure out a way to easily get it on. The metal wires in the hose run clockwise and I was trying to screw and push the nipple in the same direction. As you do that all you do is decrease the diameter of the hose making it harder. I then tried to screw and push in the nipple counterclockwise and it went it very easily.
The metal wire is built into the hose, sandwiched in between two layers of plastic so it never comes in contact with any water. These hose are made for pond and Ive seen them sold in reef stores more than one occasion, so Im sure its reef safe it thats what your getting at.