
1) Turn OFF cold water supply to RO system. Turn OFF the tank ball valve. Turn on RO faucet lever briefly to relieve the built-
up pressure inside the RO system. This will make opening the housings easier.
2) Open housing: Have the RO standing upright. Slip the plastic wrench onto the #1 housing. Looking down from a top
view, you should open the housing turning clockwise. If necessary, lay RO down on the floor to get a better leverage. If the
housing is too tight, use a hammer and gently tap on the wrench handle to help turn the wrench.
3) Discard 3 used filters, wash housings with mild soap, rinse off. Put 3 new filters into their respective housings: sediment filter
in stage-1, carbon block filters in stages 2 & 3.
4) Close up the housings. Make sure each housing has a black O-ring in the thread groves. First hand tighten the housing,
then use filter wrench to fully tighten each housing.
5) Turn ON the cold water supply with the tank ball valve CLOSED with RO faucet lever turned on. Please let purified water
flow run for 10-15 minutes to a normal water stream to relieve built-up pressure inside the RO unit then turn OFF the RO
faucet lever and OPEN the tank ball valve.
6) Turn OFF the RO faucet lever and OPEN the tank ball valve.
7) Check for leaks!
APEC R.O. System Filter Change Instruction
Changing Stages 1, 2, 3 Pre-Filters: (should be changed at least every 12 months)
Changing Stage-4 Membrane: (should be changed every 3-5 years)
1) Turn OFF the cold water supply to RO system. Turn OFF the tank ball-valve. Lift up RO faucet lever briefly to relief the built-
up pressure inside the RO system. This will make opening the housings easier.
2) See Fig. B. Locate the Membrane housing on the system (labeled “Membrane”). Remove the WHITE tubing from the hous-
ing’s cap at point D. To remove tubing, Push In and Hold Down on the collet ring square against the fitting. With the collet
held in this position the tube can be removed. Open up the cap (turn counter-clockwise) see Fig. A1. Using a plier, remove
the used membrane for disposal.
3) Once the membrane is removed, please tilt the RO system at an angle to drain out residual water from inside the mem-
brane housing and insert the new membrane using a plier. Push membrane into housing. Avoid touching the Membrane
with your hands to prevent contamination.
4) Important! Make sure the “double-ring” end of the membrane goes into the housing first as shown in Fig. A2. above. The
membrane cannot filter water if it’s inserted in the WRONG direction!
Add a little bit lubricant on double o-rings.
Fig. A2
Correct direction
After Taking the housings off, take out the dirty
filters and put the new 3 pre-filters in. Remember,
Stage-2 and Stage-3 are the same carbon filters.
Fig. A1
Turn counter-clockwise to
open the membrane
housing cap.

Changing Stage-5 Carbon TCR Filter: (should be changed every 3-5 years with Membrane)
1) Remove the OLD filter: See Fig. B. Disconnect the Input tubing from point J and Output tubing from
point H. To remove the tubing, Push In and hold down on the collet ring square against the fitting. With the
collet held in this position the tube can be removed. Unclip the filter from the membrane housing and discard
the used filter.
2) Sanitize: Use some mild bleach solution to rinse the 2 tubing ends, and the 2 ports of the new filter. This is to
prevent contamination.
3) Install NEW Filter: Put the filter back onto the membrane housing. Make sure the “FLOW ” on the filter is
pointing to the pure water output direction.
NOTE: The QC filter will come with 2 end plugs.
Please remove both end plugs before
reattaching tubing. See Fig. C.
4) Connect the Tee fitting on the Inlet (J) of the filter. Push the tubing into the QC fitting on the filter, then gently
pull back on make sure connection was secure. Lastly connect pure water output line to Outlet (H) on filter.
5) Check for leaks!
Fig. B
Top View
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Fig. C
5) Close the housing cap. Reconnect the WHITE tubing to the cap. Turn on the cold water supply and tank valve. Let the RO
system run to re-fill the tank (takes about 2-3 hours).
6) Check for leaks!
7) Drain the first tank of water (through faucet) to flush out the new membrane! The 2
nd
tank of water is ready for use.
