Water softner for installation in your shower using your existing handheld shower head.

Supplies

12" section of 3" PVC pipe
2 ea. 3" PVC couplers
2 ea. 3" to 1.5" PVC reducers
2 ea. 1.5" to 1/2" NPT PVC
2 ea. 1/2" NPT male to 1/2"G male adapter
1/2G shower hose
Water softner resin
Handheld shower head of your choice if you don't have one already. Use the style that have a built in diverter and attach to the shower arm pipe work best.
120 micron filter screen
3D printed screen holders (see additional details below)
Silicone caulk
PCV primer and solvent
Teflon tape and/or pipe thread compound

Step 1: Making the Filter Screens

Print two sets of each of the .stl files. One set of each will be needed for each end of the 3" pipe. Each of these have a small 1 degree taper. Make sure align the taper correctly when gluing and installing in the pipe.

Using CA glue (Super Glue), glue a 3" square of the screen material to the larger side of the taper of the "Body". It works best to lay the screen flat on wax paper and then place the ring on top and then some weight on the ring while it dries. After it dries, trim the excess screen from around the ring to make it perfectly round.

Then glue the smaller side of the "Body_Back" to the screen side of the previously glued screen and ring to make a screen sandwich. Be very careful to align both rings as well as possible before the glue sets. You don't want the two rings to be offset.

Note: both rings have a 1 degree taper to them that is hard to see, but this makes them easier to slide in to the pipe. The "Body" file is the smaller of the two and should go in first.

Step 2: Install the First Filter

Cut the 3" pipe to about 12". You can make it longer or shorter if you wish. Longer will give you more capacity.

Sand 1.5" of the inside of both ends of the pipe. This will give a better surface to adhere to. Use silicone caulk on the inside inch of the pipe and also apply a thin layer of caulk to the outside of the filter screen ring (keep in mind the taper, the smaller taper should go in first). Only install one side of the pipe at this time.

If the ring is too tight, you can file the outer edges of the rings to knock off the high spots to help it slip in better. There may be differences in tolerances between your pipe and my pipe.

Step 3: Install the Softner Resin

Cut a 1" corner off of the resin bag. These things can get very messy if allowed to spill. Squeeze out the resin into the open side of the pipe. Do NOT fill all the way. Only fill to about 80%. Leave at least 3" from the top of the pipe.

Caulk the inside of the pipe and the remaining filter ring as previously and install the filter ring flush with the end of the pipe. Again, keep in mind the taper of the rings. The smallest side should go in first.

Step 4: Glue the Fittings

Using PVC primer and glue solvent, glue the couplers on the pipe first. Make sure to hold the coupler tight on the pipe while the glue sets, they tend to want to back off. Also glue the reducer and the adapter in the order of the photo.

Once the glue is good and dry, using teflon tape and pipe thread compound on the threads of the brass adapter, install the adapter all the way. Make sure the thread the tapered NTP threads into the PVC fittings. The two threads of the adapter are not the same! They look the same. The 1/2G is NOT tapered and those are for the shower hose fittings.

Step 5: Installation

Install the diverter valve that came with your handheld shower head on the shower arm pipe. Next, install the additional extension hose on the diverter valve and then to one side of the softner. Make sure to use the o-ring seals in the fittings. Tighten just over hand tight. The attach the hose that came with your handheld shower head to the other side of the softner and tighten just over hand tight. Mount the shower head on the holder.

Turn on the water slowly and let it fill up while checking for leaks. Do not use the softner with the shower head in the off position, it's not designed to take full line pressure (although it will and should not be a problem).

Step 6: Regeneration

As with any resin bed water softner, they will need to be regenerated from time to time. Whole house water softners do this automatically based upon water usage or time elapsed. The frequency of regeneration depends greatly on the hardness of the source water, water usage, and grains of resin. This build does not contain a large amount of resin so it's considered to have a fairly low grain capacity. However since it's not softening water for the entire house, only the shower, it doesn't require the same capacity as a whole house system does.

I cannot tell you how often you will need to regenerate it because everyone's source water is different. It helps if you have a test kit to know how hard your source water is and also helps to test to know when it's time to regenerate.

In order to regenerate the softner, fill a container with about 1/2 gallon of water. Add salt to the water until it no longer dissolves in the water. This may take a cup or two of salt. This will create a salt brine solution. A 12" pipe will have a volume about about 1/3 of a gallon, but less with the resin.

Uninstall the softner from the fittings. Drain the excess water from the softner. Plug one end. Fill the softner with the brine solution. You may not need all of the brine. Make note of how much you need to fill the pipe for next time. Let the brine solution sit inside for about an hour then drain. Reinstall the softner and rinse for about a minute.

These are general guidelines and you may have to adjust for your situation.