RO/DI units??

[Putty]

I just went and bought one today. I got this one.

100gpd model
http://www.bigalsonline.com/Fish_Hi-Tech-Department_Reverse-Osmosis-Units_Barracuda-RO-Units.html?tc=default

Did not come with a TDS meter. Can I add one later or should I just get the handheld one and be done with it. I plan to hook it up today when I get home connecting it to my refrigerator water line. Wise or no?

[sporto0]

I use a handheld TDS meter so that I know when to change out the filters or resin, I don't think it matters which you use, any cold water line is fine as long as your getting the proper PSI for your unit.

[Reefing Newbie]

With the model I am thinking of purchasing, I was told that all you need to do to tell when the filters need replacing, is look at the filters to see what color they are. When they become rust colored, it is time to change. I cannot remember what model it is, but I would assume it works on all of them where you can see the filters.

[Putty]

Here is where I am confused. My friend has one that came with a propane looking tank that holds water the unit makes. Mine does not have that, so once mine is all connected and I want water, I assume I just grab the hose and spill the water into a container.
Then I was told you dont want to have them running all the time and some people install a auto shutoff switch. Does this mean I need to valve or something on the hose to stop the water from running to it when I dont want to use it??

[sporto0]

With the model I am thinking of purchasing, I was told that all you need to do to tell when the filters need replacing, is look at the filters to see what color they are. When they become rust colored, it is time to change. I cannot remember what model it is, but I would assume it works on all of them where you can see the filters.


The only thing you can change by sight is the sediment cartridge & possibly the DI resin if it's color changing, but even then I like to make sure that TDS readings are zero coming out of the unit. There is no visual way of telling if your carbon block or membrane need changing.

[sporto0]

Here is where I am confused. My friend has one that came with a propane looking tank that holds water the unit makes. Mine does not have that, so once mine is all connected and I want water, I assume I just grab the hose and spill the water into a container.
Then I was told you dont want to have them running all the time and some people install a auto shutoff switch. Does this mean I need to valve or something on the hose to stop the water from running to it when I dont want to use it??


The propane looking tank is usually used to store drinking water, you don't want that, & most definetly you need a shut off valve. I have a garden hose adapter on mine & just use it in my utility tub in the basement, I bought a 55 gal plastic rain barrel & I use that to store my RO/DI water, i also keep a small powerhead & a heater in there. There will be a water inlet line, going into the unit & a water outlet line that produces the filtered water. I suggest installing a flush kit on the unit, it will extend the life of your membrane as well.

[Putty]

The propane looking tank is usually used to store drinking water, you don't want that, & most definetly you need a shut off valve. I have a garden hose adapter on mine & just use it in my utility tub in the basement, I bought a 55 gal plastic rain barrel & I use that to store my RO/DI water, i also keep a small powerhead & a heater in there. There will be a water inlet line, going into the unit & a water outlet line that produces the filtered water. I suggest installing a flush kit on the unit, it will extend the life of your membrane as well.

So lets say right now..you have a 55g container with water in it and don't really need it right now?
Say I do a 15g water change...Is it possible to grab the outlet hose and have it fill a container with 15g or does it not produce that quickly? I will hit lowes today for a flush kit and a shutoff valve.

Thanks!

[blt]

Is it possible to grab the outlet hose and have it fill a container with 15g or does it not produce that quickly?

A 100GPD unit will take just over 3 and a half hours to produce 15g.

[sporto0]

A 100GPD unit will take just over 3 and a half hours to produce 15g.


+1 exactly

[Putty]

A 100GPD unit will take just over 3 and a half hours to produce 15g.


Ahhh, ok! So when I want to use it I need to do what Sport does...just run it into a container with a pump and heater. To avoid standing around, I assume I can put the hose into my container and just walk away and let it fill at it's own pace.

[blt]

Yep. Just make sure you set a timer for yourself and put the container somewhere that can handle a flood if you forget about it (like in a bath tub).

[Putty]

hahahah!! Good thinking and thanks!!!

[jcw]

Can someone explain the shut off valve and flush kit?

If I have a booster pump and a faucet adapter, can I unplug the pump and turn off the inlet water to shut it down or did I read somewhere that that damages something?

[sporto0]

Can someone explain the shut off valve and flush kit?

If I have a booster pump and a faucet adapter, can I unplug the pump and turn off the inlet water to shut it down or did I read somewhere that that damages something?


I don't know anything about damages, you have to shut the pump down when you turn off the water to the pump & unit or the pump will burn up? Is that what your asking? A flush kit is installed to your unit inline so that you can turn the flush valve once a week or so to directly flush out your membrane & then easily close valve to resume normal filtering.

[Putty]

Very simple install. I was only halted due to no place to mount it. Poured wall basement. Will have to fabricate a bracket.

[Orcrone]

Can someone explain the shut off valve and flush kit?

If I have a booster pump and a faucet adapter, can I unplug the pump and turn off the inlet water to shut it down or did I read somewhere that that damages something?

Shut off valves are used to turn off water to your system. They're generally used in conjunction with float switches. If your container gets full a float valve will raise up. The back pressure will cause the shut off valve to engage, killing the water to the system. I've also seen them used with moisture sensors to turn off the system if water is detected on the floor.

A flush kit is used to flush the membrane. I use it for a minute or two when I first start producing RO water and finish producing it every time I use the system. It will help extend the life of your RO membranes.

Generally booster pumps come with pressure switches. When you turn on the water the pump turns on, when you turn off the water the pump does the same.

[jcw]

Shut off valves are used to turn off water to your system. They're generally used in conjunction with float switches. If your container gets full a float valve will raise up. The back pressure will cause the shut off valve to engage, killing the water to the system. I've also seen them used with moisture sensors to turn off the system if water is detected on the floor.

A flush kit is used to flush the membrane. I use it for a minute or two when I first start producing RO water and finish producing it every time I use the system. It will help extend the life of your RO membranes.

Generally booster pumps come with pressure switches. When you turn on the water the pump turns on, when you turn off the water the pump does the same.

Thanks!

So obviously the float valve shuts off the water on the outlet side. Does the remaining pressure in the system damage the membranes as well? and that's the reason for a shut off valve?

I'll look into whether my spectrapure system has one or a flush kit. I bought it used.

[Dave71]

A couple of thoughts.

First, there are a number of videos on YouTube that explain the various components/options etc and as they say, a picture is worth a 1000 words.

Generally, the in line TDS meter is considered better to use, for two main reasons.

One, it is right there with the unit, and you are therefore more likely to use it. i.e. no chance of misplacing it and no need to search for it, just flip the switch.

Two, since it is in line, the water sample/sensor will not become contaminated giving you a false reading. Hand held units have the potential for false readings. This is not to say a hand held unit is not acceptable. Just saying the in line is better.

Last, to your question, there is no problem buying an in-line unit now, and installing it yourself. Very easy.

[Buckeye Hydro]

With the model I am thinking of purchasing, I was told that all you need to do to tell when the filters need replacing, is look at the filters to see what color they are.

Ugh. Here's some better advice:

A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the usable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or both of the filters is beginning to clog.

Also be cognizant of the chlorine capacity of the carbon block. A good 0.5 micron carbon block for example will remove 99% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Some original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons.

Regarding your RO membrane and DI resin, use your TDS meter to measure, record, and track the TDS (expressed in parts per million) in three places:
1. Tap water
2. After the RO but before the DI
3. After the DI.

The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 parts per million (ppm). Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?

If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block filter (collectively called “prefilters”) do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in” port on your RO housing and you'll see it is still approximately 400 ppm.

The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 90% (i.e., they reject 90% of the dissolved solids in feed water). So the purified water coming from your 100 gpd membrane would be about 40 ppm (a 90% reduction). Filmtec 75 gpd (and below) membranes produce less purified water (aka “permeate”), but have a higher rejection rate (96 to 98%). The life span of a RO membrane is dependent upon how much water you run through it, and how dirty the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the total dissolved solids (TDS) in the water coming in to the membrane, and in the purified water (permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. Membranes also commonly produce less water as their function declines.

After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the 40 ppm water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm, you know that your resin needs to be replaced. Sometimes people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin “dirty” water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal.

Russ

[Buckeye Hydro]

A float valve like this:
http://i224.photobucket.com/albums/dd293/BuckeyeFS/adjfloatvalvewgraph.jpg

will stop the flow of purified water. An auto shut off valve like one of these:

http://i224.photobucket.com/albums/dd293/BuckeyeFS/_MG_4800.jpg

senses when the float valve is closed, and stops the flow of waste water.

Russ

[Buckeye Hydro]

A couple of thoughts.

First, there are a number of videos on YouTube that explain the various components/options etc and as they say, a picture is worth a 1000 words.

Generally, the in line TDS meter is considered better to use, for two main reasons.

One, it is right there with the unit, and you are therefore more likely to use it. i.e. no chance of misplacing it and no need to search for it, just flip the switch.

Two, since it is in line, the water sample/sensor will not become contaminated giving you a false reading. Hand held units have the potential for false readings. This is not to say a hand held unit is not acceptable. Just saying the in line is better.

Last, to your question, there is no problem buying an in-line unit now, and installing it yourself. Very easy.

We'll respectfully disagree with Dave here.

Inline meters like this for instance, which have TWO probes
http://i224.photobucket.com/albums/dd293/BuckeyeFS/dm1_web.jpg

are preferred by some because they are convenient.

However, remember that you ideally want to be able to measure TDS in THREE locations: tap water, RO water, DI water. Handheld meters are generally more precise than the inline meters for a number of reasons.

Russ

[Lorenz725]

Thanks for taking the time to explain all that Russ. It helped me with some questions I have had!

[Buckeye Hydro]

Glad to help!

[Dave71]

We'll respectfully disagree with Dave here.

However, remember that you ideally want to be able to measure TDS in THREE locations: tap water, RO water, DI water. Handheld meters are generally more precise than the inline meters for a number of reasons.

Russ

I would agree, we'll respectfully disagree.

Use of in line meters vs handheld has little to do with the number of locations you are testing other than potentially cost. i.e. you can buy in line meters to test in as many locations as your heart desires.

Having used both styles of meters myself, I can only speak to my experience, and numerous others that have provided similar feedback.

Convenience can play an important role in the liklihood of using them, and accuracy of in line meters has not been generally cited as a concern of aquarists.

[Buckeye Hydro]

True - its easy enough to test in three locations (or more) with inline meters. We carry inline meters with two probes, and inline meters with one probe.

However, what we see in the vast majority of cases where people use inline meters, they only use one inline meter which has two probes. When we try to troubleshoot their RO membrane with them they can't tell us the TDS of their feedwater.

Don't get me wrong - inline meters are nice. If I were to use them I'd get two meters, one with a single and one with double probes, and make sure the probes are aligned correctly.

Russ