Need RO set up help...

[GreenSpottedPuffer]

Ok, thanks...

SO I used a brass "T" from that shut off valve that was already there that Tees up to the faucet and also to the RO unit...It says its a compression fitting and the guy at HD said all I need to do is insert the tubing and then tighten the nut. I have done that but it leaks. Am I missing something? Was there suppose to be a washer or something? Or have I probably just not tightened it enough?

I also realized that having this hooked up to the coldwater line means I am using very cold water. I though to make RO water it was suppose to be around 70-75 degrees? Am I wrong?