I need instructions for changing the bladder on an under sink reverse osmosis system

You can get replacement cartridges for all the H series through AC series RO systems on line from several suppliers. I use them and they work just fine.
RJH2O

That's the drain for the reverse osmosis system. It should be tied into a waste line under the sink.
RJH2O

The storage tank probably has low air pressure. On a 3 gallon RO tank empty the tank completely of water and adjust tank pressure to 7psi.
RJ

Is this a reverse osmosis drinking water system? If it is it is an H8 RO. If so shut the water off that feeds the RO. The leak is probably coming from one of the fittings, they can be cut by the compression fittings and leak.
RJ

A TDS (total dissolved solids)meter is needed to test the Reverse Osmosis water and compare it to the feed water to determine how much TDS is being removed. Reverse osmosis membranes are designed to remove 80-95% of the TDS in your water supply.

For example: If your water has 500ppm of TDS the minimum TDS removal should be 400ppm leaving 100ppm. If the TDS from the Reverse Osmosis System drops to these levels it is time to change the Membrane.
Typically an RO system will consistently remove 90+% of TDS for many years. The normal lifespan for a membrane can be anywhere from 3-10 years. It all depends on the TDS of your water and your water usage. The higher the TDS the more frequently the membrane needs replacing. The other filters should be replaced every 6 months to keep the quality up and protect the membrane.
A TDS of 1000ppm compared to 100ppm is much more difficult remove to acceptable levels. I like to compare 1000TDS to taking muddy water, forcing it through a filter and getting drinking water. Where 100TDS may be more like a clear glass of water. Consequently a reverse osmosis system on high TDS will be less efficient, less gallons produced and filters will need to be changed more frequently to keep the quality and quantity up.
RJ

If you want the reverse osmosis water to go to the ice maker then you tap in to the line that feeds the spiget on the sink.

Typically a reverse osmosis storage tank should have a precharge of approximately 7 psi. Depending on the make/model of your tank it may have a higher charge currently which would cause the tank to not fill. There should be a schrader valve on the bottom or side of the tank. Using a tire gauge and bicycle pump you should be able to check the current pressure in the tank and adjust it up or down to 7 psi.

reverse osmosis storage tanks: http://www.freshwatersystems.com/c-32-reverse-osmosis-storage-tanks.aspx

Geoff D., CWS-I - WQA Certified Water Specialist
Fresh Water Systems, Inc - http://www.freshwatersystems.com 1.877.335.3339

I am assuming based on your description that the system you have is a reverse osmosis system. If this is true, you most likely need to recharge the air pressure in your RO storage tank. I have included step-by-step instructions below. If you find that your tank is not holding air or the tank will not empty completely, the bladder inside the tank may be broken and the tank will need to be replaced. I have included a link to our selection of RO tanks as well. To recharge the tank you will need a bicycle tire pump and a tire gauge that will be capable of reading below 10 psi. If you don’t have one that reads in single psi increments, then a meter that starts at 5 psi will work.
http://www.freshwatersystems.com/c-32-reverse-osmosis-storage-tanks.aspx

1) Close the cold water feed valve (if you can’t locate this on your system, you may be able to turn off the cold water to your sink)
2) With the RO tank valve on, locate the valve stem on the bottom or side of the tank. (this will look like the air stem on a bicycle or car tire)
3) Remove the stem cap.
4) Drain all water out of tank through open RO faucet into sink. (Continue to leave the RO
faucet open throughout the entire procedure)
5) If the current tank pressure doesn’t empty the tank, apply tire pump to valve stem
and pump a few times. Flow will increase and then gradually decrease as
pressure equalizes. Do not overcharge the bladder during this procedure.
6) Repeat step #4 and #5 until tank is completely empty. (Tank is empty when additional
pumping produces no more water)
7) At this point, adjust EMPTY tank to exactly 7psi. (Gauge reading midway between 5
& 10psi is sufficient)
8) Turn off RO faucet.
9) Replace cap on valve stem
10) Open cold water feed valve.
11) The water is useable immediately; however, tank will take a few hours to completely fill.


Geoff D., CWS-I - WQA Certified Water Specialist
Fresh Water Systems, Inc - http://www.freshwatersystems.com 1.877.335.3339

a pump will help you