Planning a RO undersink install
#1
Member
Thread Starter

Hi everyone (been a while!)
I have two questions on installing an under sink RO system:
Here is a pic of the underside of my sink-- I am also concerned that the cold water shutoff may need to be replaced-- looks like it leaked at some point
I have two questions on installing an under sink RO system:
- Do I have enough room to tap into the drain above the P Trap? See pic-- with the dishwasher drain there, I am concerned I do not have enough room
- I am considering installing directly underneath kitchen, in unfinished basement. Are there any tank mounts out there? Something where I could hang/mount the tank from the ceiling joists? Any issues with system and daylight through a window (potentially damaging vinyl tubing?)?
Here is a pic of the underside of my sink-- I am also concerned that the cold water shutoff may need to be replaced-- looks like it leaked at some point

#2
Not knowing what your drain tap looks like it's tough to say for sure.
If mounting the tank in the basement just mount everything there, that is how I have my set up, it saves all your under counter space.
As for the tank, a couple of shelf brackets and piece of plywood and your good, it's only a couple of gallons of water.
If mounting the tank in the basement just mount everything there, that is how I have my set up, it saves all your under counter space.
As for the tank, a couple of shelf brackets and piece of plywood and your good, it's only a couple of gallons of water.
#3
Group Moderator
I have my system installed in the basement and it works out well. It's helpful to have the room as it can sometimes be a wrestling match getting the tanks unscrewed for filter changes.
I do not know of any components in an RO system that can be damaged by exposure to sunlight. I can't imagine yours will get direct sun in the basement so it would only be indirect light at the worst. Read the manual for your system to be certain but I think it's OK to install it in a place where there is light.
I do not know of any components in an RO system that can be damaged by exposure to sunlight. I can't imagine yours will get direct sun in the basement so it would only be indirect light at the worst. Read the manual for your system to be certain but I think it's OK to install it in a place where there is light.
#4
Member
Thread Starter
Hi Marq1
Drain tap? Sorry-- does this mean something other than the down pipe from the sink (shown in pic)?
Let me know, and I can take another picture tonight.
Drain tap? Sorry-- does this mean something other than the down pipe from the sink (shown in pic)?
Let me know, and I can take another picture tonight.
#5
Do I have enough room to tap into the drain above the P Trap?
No idea what your tap looks like, you have the eyes on the parts!
#6
Member
Thread Starter
oh! The drain tap in the RO kit! 
Have to wait for it to arrive then. Dont have the part, yet.
.

Have to wait for it to arrive then. Dont have the part, yet.

#7
Group Moderator
If you are installing the RO in your basement do you have another drain you can route the waste water to?
#8
Member
Thread Starter
Unfortunately, I do not. The only other option would be a long run to a sump pit-- I dont think that is smiled upon in these parts (have to check with town). The RO manufacturer said as long as I am no more than 15' away, I should be fine--just might have more TDS in final product
This is why, if I install in basement, I am considering building a shelf off ceiling joists/floor joists of kitchen
This is why, if I install in basement, I am considering building a shelf off ceiling joists/floor joists of kitchen
#9
Member
Thread Starter
Finally got the kit in-- here are pics
The RO kit arrived yesterday. Here are some pics.
Basically, I need to decide:
I didnt have a chance to measure distances, but by counting 8" tall basement blocks in the wall, I estimated its about 48" from basement countertop to joist. Joist looks to be 2x8 or 2x10. Then, in kitchen cabinet, its maybe another foot or so to the drain.
Just trying to determine if I can get away with just placing the kit on that basement countertop, or if I need to shorten the runs by either putting a shelf on the cinderblock wall (I really dont have much luck mounting things to block--even with tapcons/anchors/etc!) or bulding a shelf for the tank below all the pipes you see in the following pictures.
I also thought of the (not very exciting) possibility of running the drain line to the laundry room utility sink, which would limit the vertical rise of the drain line. My house is a 1960s era split level. So the joists of the basement ceiling are roughly just above the cement slab floor of the laundry room. My preference would be to just go up and tap in to kitchen sink drain, but the vertical rise, plus the lack of real estate above the P trap has me concerned.
Here is what we are dealing with:
Basement placement options

Kitchen Sink, attempting dry fit of drain tap saddle. Best location in terms of fit

Kitchen Sink, attempting dry fit of drain tap saddle. I would have preferred here, but saddle wont fit above dishwasher drain whye

As requested, Marq1, here is a picture of the drain tap
Basically, I need to decide:
- Where do I want to install the tank and filters? I have the original cabinest/counters to the house in my basement (house came like this!). Is this too long a run to the sink directly above?
- If I put the filter on this cabinet, or even if I suspend it from joists above, I have 3 options I can think of, in terms of the drain line. Option1 : Run the drain up to the sink (too long a run? 48" from counter top to joists, plus another 2-3 feet to the drain); Option 2: Run the drain the length of the basement to sump pit (is this even allowed?); Option 3: Drill through header to the laundry room to the right of install (see pic). There is utility sink there I could drain into
- If I stick with original plan regarding drain, and run to kitchen sink directly above basement install, is it safe to install drain saddle on the reducing fitting as shown in the picture? Its pretty much the only place it fits
I didnt have a chance to measure distances, but by counting 8" tall basement blocks in the wall, I estimated its about 48" from basement countertop to joist. Joist looks to be 2x8 or 2x10. Then, in kitchen cabinet, its maybe another foot or so to the drain.
Just trying to determine if I can get away with just placing the kit on that basement countertop, or if I need to shorten the runs by either putting a shelf on the cinderblock wall (I really dont have much luck mounting things to block--even with tapcons/anchors/etc!) or bulding a shelf for the tank below all the pipes you see in the following pictures.
I also thought of the (not very exciting) possibility of running the drain line to the laundry room utility sink, which would limit the vertical rise of the drain line. My house is a 1960s era split level. So the joists of the basement ceiling are roughly just above the cement slab floor of the laundry room. My preference would be to just go up and tap in to kitchen sink drain, but the vertical rise, plus the lack of real estate above the P trap has me concerned.
Here is what we are dealing with:
Basement placement options

Kitchen Sink, attempting dry fit of drain tap saddle. Best location in terms of fit

Kitchen Sink, attempting dry fit of drain tap saddle. I would have preferred here, but saddle wont fit above dishwasher drain whye

As requested, Marq1, here is a picture of the drain tap

#10
The water line will be under pressure so sitting on the floor, on the cabinet or under the floor joists are no issue.
Install where it is easy to get to the filters!
I am not aware if the drain has any pressure so going up may not be good, somebody else can comment.
Mine drains to sump which drains to creek, if sump drains to sewer system, well thats an issue more than RO going to sump!
Install where it is easy to get to the filters!
I am not aware if the drain has any pressure so going up may not be good, somebody else can comment.
Mine drains to sump which drains to creek, if sump drains to sewer system, well thats an issue more than RO going to sump!