Increasing RO Output Question

[DiscusLoverJeff]

Hello,

Here is a link to the brand of RO unit I am currently using.

http://www.maxwaterflow.com/5-Stage-50-GPD-Reverse-Osmosis-System-With-Two-phase-Faucet-_p_251.html

I was reading the sticky in this part of the forum but its a bit outdated and the pictures are gone. I want to find out if I can just replace the membrane in this unit to a larger more productive one to get a 150 gpd (gallons per day) instead of my 50 gpd? If so, what do I need to replace, just the membrane?

All the units for the different gpd look the same so I am assuming its only one or two things that may need replacing. Can I buy the membrane as Home Depot or equivalent? I have seen RO units sold there.

Also from the first "sticky" in this section it says for more gpd you can increase the temperature but if you are running through your cold water return, there is no real way of increasing temp correct? Running through your hot water would not be effective if you are wasting hot water and not to mention the added money heating up water all day.

[NanDiscus]

Hi Jeff,

All you have to do to replace the membrane is take out the old one, put the new one in and -this is important- replace the existing flow restrictor for a #800 or #850 or even #950, depending on which one you can get. This sounds so simple, doesn't it? :)
I haven't had a very good look at the pic under the link you posted to see whether the flow restrictor on your unit is built into the membrane housing or it is fitted separately into the waste-water line. If it's built in, then you have to take it out (normally it is INSIDE the fitting on the waste-end of the membrane housing) and put the new one (inline-type) after the fitting where it's not in the way. You may have a flow-restrictor with a built-in flush valve. In this case you have to DIY your own flush valve and to do it you need to get 2x 1/4" T-fittings and a 1/4" inline tap, which is used to bypass the flow-restrictor when it's open. That's how you flush the membrane, by the way.
I looked at the membranes on the site you linked in, but I wasn't too impressed.
If you use a lot of RO water, then you should also consider upgrading your prefilters.

One thing to keep in mind - when it comes to RO-units, quality parts ALWAYS pay for themselves in the long run. ;)

Nandi

[DiscusLoverJeff]

Thanks Nandi for the information.

I will look into the restrictor part but I am attaching some drawings of the membrane area. Can you tell me if you see the restrictor because I do not.

Also, what brand of filters do you reccommend?

http://i752.photobucket.com/albums/xx161/DiscusJeff/Personal/img366.jpg?t=1292780023

http://i752.photobucket.com/albums/xx161/DiscusJeff/Personal/img367.jpg?t=1292780264

[nc0gnet0]

The problem with hooking up your RO unit to your hot water heater is two fold, one the incrdeble waste and two, if you get to hot (above 110) you will destroy the membrane.

[nc0gnet0]

Another option is to add a second membrane and housing to your system, and piggy back them, while still using the same prefilters and post filter, this is what I have done. Then all you will need are a few "t's".

[NanDiscus]

Jeff,

If you look at the first picture, you see the flow restrictor fitted into the waste water line, that bluish thingy right under the membrane housing. This is what you have to replace with one of the types (ml/hour ratings) I suggested above. Your system does not come with a membrane flush valve, so if you would like to be able to extend the life of your membrane, you might want to install one of them. Just cut the tubing on both ends of the flow restrictor, about 2" away from it, reconnect with the straight side of the T's and fit the little plastic valve in between so when you open it you can bypass the flow-restrictor (meaning, that the pressure will force the water parallel with the sheets of the membrane, flushing the 'guano' off the surface of it), like this:

┬─flow restrictor─┬──to waste───
│
└──flush valve──┘


nc0gnet0 had two good points there. Hot water will bust your membrane, unless you have one of those fancy faucets with auto temp. control which you can set to any temps you like. 70-75F would be a very safe bet, but then you have to take into account the cost of heating the water. I don't think it's worth the effort either.
It is in fact a far more feasible idea to use two membranes, but I only suggest you to do so if your feed water pressure is well above 60psi. The first membrane causes a pressure drop of around 12-15psi, and at 45 the second membrane is struggling under the combination of insufficient pressure and an increased feed TDS.
Basically, we could go on with the possibilites of upgrading your existing unit to the point of a 450gpd fully automatic pumped unit, but not too many people these days have that much money to invest in one go. Once again... In the long run an RO like that does pay off, especially if you are into breeding discus or breeding wilds.

I don't want to be breaking any ruleZ on here by claiming any one brand as 'first choice', but the combination of Pentek prefilters and RO-Ultratec membranes (Really made in the USA, it's not only the sticker that says so...) have served me perfectly for many years now. I'm sure that there are sponsors on Simply who can sort you out. ;)

Nandi

[Ed13]

Just glanced throught the thread really, but if you have a standard residential RO system you can replace the membrane for a higher production one. You'll need to replace/adjust the flow restrictor or maybe even replace the type of it.
Most 150gpd membranes I've seen are rated at above 65 psi( some higher) at 77F. Increasing your temp helps increase permeate up to a point, if I'm not mistaken most membranes are fried near 120F.

To be honest in my opnion, you ought to start by increasing the psi at the input of the membrane, then a higher performance membrane. Then you can start thinking of increasing the temp.
There are also modified setups like running multiple membranes either being piggy-backed or run in parallel, higher flow canisters instead of the usuall 1/4" or 3/8" or going to 20" canisters or bigger membranes etc. Many possibilities really.

[NanDiscus]

I recently built a 450gpd one for myself with a 36V booster pump and even at very low feed water temperatures in winter its real production is still close to its nominal. In summer it outperforms it. I use the standard 10" pods, although there might be some truth in the use of 20" prefilters - they have a higher flow rating than the regular 10" ones. Mind you... a decent 20" Pentek carbon block does not come cheap.

Nandi

[nc0gnet0]

It is in fact a far more feasible idea to use two membranes, but I only suggest you to do so if your feed water pressure is well above 60psi. The first membrane causes a pressure drop of around 12-15psi, and at 45 the second membrane is struggling under the combination of insufficient pressure and an increased feed TDS.

I don't understand why you think there would be an increased feed TDS, both membranes would have the same input water. As for the drop in pressure, it should be minimal, I only experiance a 2psi drop, this is with 75psi at the spicket. Perhaps we are talking about a different setup? Mine has the supply water running through the sediment filter into the carbon block/1 micron filter then is "T'ed" to feed two membranes, each with its own manual flush valve. From the two outputs of these individual mambranes it is then run into a second "T" and into the final two carbon blocks (thesed used to be DI filters but I swapped them for additional carbon blocks. The only time I could see an increase in input TDS is if you were to take the waste water from the first membrane and input it into the second mambrane to decrease waste water, something I may try next.

[DiscusLoverJeff]

Wow, thank all of you for some great ideas and advice.

Nandi, is the flow restrictor something that can be purchased at say Home Depot? I like the idea of adding a flush valve too. I don't know what my psi is at the moment but I will try and attempt to find someone who could help me figure that out. I am sure I can get a gage as someone mentioned.

One question though, if the flow restrictor is going to the waste water, how do I increase the good water other than the membrane or is that all I need at this point?

[jimg]

I don't understand why you think there would be an increased feed TDS, both membranes would have the same input water. As for the drop in pressure, it should be minimal, I only experiance a 2psi drop, this is with 75psi at the spicket. Perhaps we are talking about a different setup? Mine has the supply water running through the sediment filter into the carbon block/1 micron filter then is "T'ed" to feed two membranes, each with its own manual flush valve. From the two outputs of these individual mambranes it is then run into a second "T" and into the final two carbon blocks (thesed used to be DI filters but I swapped them for additional carbon blocks. The only time I could see an increase in input TDS is if you were to take the waste water from the first membrane and input it into the second mambrane to decrease waste water, something I may try next.

I run 2 ro systems one waste to drain the other waste to storage. I am going to try using the waste for the second unit.Problem may be that my pressure is at 48psi in and 32after ro system, so mine drops too. I'll have to check restrictor

[Ed13]

I don't understand why you think there would be an increased feed TDS, both membranes would have the same input water. As for the drop in pressure, it should be minimal, I only experiance a 2psi drop, this is with 75psi at the spicket. Perhaps we are talking about a different setup? Mine has the supply water running through the sediment filter into the carbon block/1 micron filter then is "T'ed" to feed two membranes, each with its own manual flush valve. From the two outputs of these individual mambranes it is then run into a second "T" and into the final two carbon blocks (thesed used to be DI filters but I swapped them for additional carbon blocks. The only time I could see an increase in input TDS is if you were to take the waste water from the first membrane and input it into the second mambrane to decrease waste water, something I may try next.
Yes, he is talking about piggy-backing or using the waste of the first membrane to run the second. Thruth be told, running them as parallel would give you better quality water, but it may not be neccesary for discus related purposses. Not to mention equal exhaustion from the membrane.

Wow, thank all of you for some great ideas and advice.

Nandi, is the flow restrictor something that can be purchased at say Home Depot? I like the idea of adding a flush valve too. I don't know what my psi is at the moment but I will try and attempt to find someone who could help me figure that out. I am sure I can get a gage as someone mentioned.

One question though, if the flow restrictor is going to the waste water, how do I increase the good water other than the membrane or is that all I need at this point?
Your Home Depot may very well carry it, but this may be something one might want to look at more specialized stores. Several on-line stores specializing in RO systems will have it and ready to istall flush kits too. A flush system can actually be assembled from Home Depot parts, well at least my local Home Depots carry the correct parts.

I run 2 ro systems one waste to drain the other waste to storage. I am going to try using the waste for the second unit.Problem may be that my pressure is at 48psi in and 32after ro system, so mine drops too. I'll have to check restrictor
No problem really. If you want to run two membranes, either piggy-backing or parallel, if possible if you get a booster pump. The booster pump will take the water from the tap and "boost" up its pressure. Sounds like you need it anyways.
If you mean to collect the waste water in a separate vessel and then run it through the Ro system that can be done too, although it will require some type of delivery pump and its a little trickier.

[jimg]

No problem really. If you want to run two membranes, either piggy-backing or parallel, if possible if you get a booster pump. The booster pump will take the water from the tap and "boost" up its pressure. Sounds like you need it anyways.
If you mean to collect the waste water in a separate vessel and then run it through the Ro system that can be done too, although it will require some type of delivery pump and its a little trickier.[/QUOTE]

I run mine on separate feed lines one to waste the other waste to barrel. I don't need a booster for 48psi. I increased incoming psi to 65 awhile ago and it didn't make a big enough change to leave it. If I was to run the second unit off the waste from the first I might need it, but I am hoping the restriction from the second will put more back pressure on the first system so it won't drop to 32. I'm sure I have to change the flow restrictor, should not drop to 32. should only drop a few lbs

[nc0gnet0]

either piggy-backing or parallel

I see, i did not know piggy backing was a referal to runing the second membrane off of the first's waste, I thought it was refered as the way you physically installed one on top of the other, IE parellel. My concern on running one off of the others waste water is the backpressue placed on the first unit resulting in a decrease in water production from the first, but I have not tried this. It does seem like a pump maybe neccesary for this to work correctly, it is something I want to play with.

[Ed13]

I run mine on separate feed lines one to waste the other waste to barrel. I don't need a booster for 48psi. I increased incoming psi to 65 awhile ago and it didn't make a big enough change to leave it. If I was to run the second unit off the waste from the first I might need it, but I am hoping the restriction from the second will put more back pressure on the first system so it won't drop to 32. I'm sure I have to change the flow restrictor, should not drop to 32. should only drop a few lbs
I'm clearly misunderstanding something here:confused: Sorry I can't be of help.

I'll say this, while you probably don't need a booster pump for 48psi since most membranes under 100gpd are rated at 50psi, it'll defenitely increase permeate and performance. It won't be an increase noticeable by the naked eye but it'll be there, unless something it's wrong. For example a 50 gpd membrane running with 48 psi at 77F will yield 48 gallons of water. Same membrane, same temp @ 65psi, it'll yield 66 gallons of pure water.
Again, I'm not quite understanding your setup and I'm FAR from an expert, but regardless you should be attempting to feed the membrane with it's minimun rated spec(most are 50 psi) to reach the advertised numbers. The flow restrictor is usually used to manipulate the waste to product ratio.

I see, i did not know piggy backing was a referal to runing the second membrane off of the first's waste, I thought it was refered as the way you physically installed one on top of the other, IE parellel. My concern on running one off of the others waste water is the backpressue placed on the first unit resulting in a decrease in water production from the first, but I have not tried this. It does seem like a pump maybe neccesary for this to work correctly, it is something I want to play with.
Well that's how I have always understood it. I understand parallel, when each membrane has it's own feed line T'd after the canisters and are running at the same time, same pressure. But, don't quote me on it, remember I'm working with a language barrier here:p

[jimg]

[QUOTE=Ed13;709565]I'm clearly misunderstanding something here:confused: Sorry I can't be of help.

I'll say this, while you probably don't need a booster pump for 48psi since most membranes under 100gpd are rated at 50psi, it'll defenitely increase permeate and performance. It won't be an increase noticeable by the naked eye but it'll be there, unless something it's wrong. For example a 50 gpd membrane running with 48 psi at 77F will yield 48 gallons of water. Same membrane, same temp @ 65psi, it'll yield 66 gallons of pure water.
Again, I'm not quite understanding your setup and I'm FAR from an expert, but regardless you should be attempting to feed the membrane with it's minimun rated spec(most are 50 psi) to reach the advertised numbers. The flow restrictor is usually used to manipulate the waste to product ratio.

never mind, I had a few ideas going at the same time!!

[DiscusLoverJeff]

Here is a link to what someone was refering to earlier in this thread about running 2 membranes.

http://www.dailymotion.com/video/xdgbdc_150-gpd-ro-upgrade-kit-installation_school