RO/DI installation questions

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Algae Fighter
May 30, 2006
Birmingham, AL
Well I'm going to attempt to install my RO/DI filter today. I plan to install it under the sink, in a semi-permanent way. I'm going to go to Lowe's in a bit to find a tee connection for my cold water supply. Then I'll hook up the supply line from the ro/di to it. I have a pic of someone else's tee connector below.

My question is about the drain line. I have done a ton of reading on forums to figure this out. I'm not a DIY person nor a plumber so I'm a little anxious about doing this! I don't want to mess it up. Most people drill a hole in their drain pipe under the sink and connect the waste line of the ro/di into that. I cannot do that. I live with my parents who would not appreciate a hole in their pipes. Plus I plan to move out within the next year with my ro/di filter. :)

One post I was reading on another forum said the drain line has to work by gravity? I could have misread it. I was planning on either draining the waste into the tub or the sink, but neither would be by gravity, as there would be some uphill movement needed. Is this possible or will I have to figure something else out?

I planned on doing the install today, but I can do atleast part of it with what I know now. :)



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I don't have an RO/DI filter, but I'm pretty sure the waste water doesn't have to go downhill with gravity, It works off of pressure so I would think the drain line would also be pressurized (Someone correct me if I'm wrong) Also, If you want you could drill a hole in the drain, and when you move out just replace the plastic drain part of the sink (the part you drilled) Just an idea..
Good question. Mine has a gravity assist on the drain line, but that wasn't intentional. I would assume that the 50psi + of water pressure behind the unit could push the water anywhere. I know on the pure water line it pushes up and down as I contort hosing to where I want it to go with no problems.
Thanks guys! I'm gonna try draining it into the tub. I don't plan to have the tubing showing all the time, just when I'm using it, so hopefully that will work.

Hopefully I can find the right part for under the sink. Otherwise, I'll just try to hook it up to the sink when I need it. I don't have a ton of counterspace though, so I'm trying to avoid that.
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