It is currently Fri Nov 17, 2017 6:33 pm
 

 

All times are UTC - 8 hours




Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Back to the GE Merlin.
PostPosted: Mon Mar 05, 2012 1:54 am 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
After owning a GE Merlin since 2007 I just wanted to give all an update on my experience.

For the first two years I had no problems with this unit. All worked fine and I continued getting a very low TDS reading, 10ppm by the end of 2009.

In Jan 2010 I moved to an apartment with no pre-softened water. In my previous home I had a whole house water softening system with sediment and GAC prefilters before the softening unit. The softening unit was a residential cation resin based unit.

Now with no water softening or pre-filtering of any kind before the Merlin unit, the first problem I encountered after several months was the manifold internal valves getting stuck. This caused the water to continue running through the system and into the drain even when the unit was not in operation. Lucky me, I now paid a flat rate of $15 per month for water, so the bill was no big issue.

But my TDS went up quickly, and so did acid flushing the membranes, which helped only partially.

I flushed my membranes twice the last two years and finally, they gave away a few months back. The adhesive which holds the rolled element composite film degraded and the membrane fouled.

I continued having manifold problems every few months.

I didn't want to give up on this nice piece of equipment so I did my research and put together what I have learned about R/O's throughout my years using them, so I thought I'd write up my conclusions and share with you how I am now taking care of my investment.

Most of us know by now that GE discontinued the Merlin and now Hydrologics makes the upgraded version called the Evolution, a relatively pricier system which produces 1000 gpd (basic) vs. the 720gpd (basic) produced by the Merlin.

Hydrologics is providing most Merlin replacements to the market.

Though it seems the Evolution and the Merlin could share membranes (that would be great), I am told they are not compatible. I don't know this for sure and it may be just a sales push by the vendors and manufacturer. We'll wait and see on this.

Now, to keep that Merlin going in shipshape, I went ahead and sterilized the manifold with hot water and chlorine, then flushed it out with high pressure water from the hose. I lubricated the manifold by generously spraying food grade silicone into all the openings and rinsed it again with high pressure and also ran the Merlin with the old membranes for several hours to make sure all the silicone was out of the system (after installing a prefilter before the Merlin - see below*) .

So I purchased two Big Blue housings to use as prefilters*.

Stage 1 receives the tapwater which runs through a 4.5 X 20 carbon block / sediment cartridge.

State 2 contains a reusable cation resin cartridge which you can empty to regenerate the resin when exhausted. This is done with a brine solution of plain salt. After soaking the resin in the brine you just rinse it out with fresh tapwater and put it back in the cartridge and into the housing. The Big Blue 4.5 X 20 inch housing contain the equivalent in filter media volume of six 2.5 X 10 inch conventional cartridges. This means that depending on your r/o water use, you will be recharging your resin (not shedding money down the drain buying the harder to recharge mixed bed resins which most people end up disposing!) six times less frequently than if you had the conventional 2.5 X 10 cartridges.

Stage 3 (Stage 1 on the Merlin) is the Merlins own GAC/sediment cartridge and Stages 4 and 5 and or course the Merlin Menbranes (just got two brand new for 186.00 delivered.

This configuration with the cation resin before the r/o membranes allows you to take out the hard ions (Ca, Mg and others) and the membranes take care of the Na ions (soft ions) reducing the alkalinity and producing a very nice pH 6.0, TDS 0.2 water, from a tap source of pH 7.4 and +/- 350ppm (average) that I have here in SLC.

I expect to be recharging resin every 3-6 months, but need to wait to see real numbers as my TDS starts to increase. This could be quite longer considering the amount of resin I am using and the volume of water I use weekly.

And again... placing your resins after your R/O membranes and using mixed bed resins is advice given only by a person who sells membranes and resins. By your resins separately, cation and anion, and place them in separate cartridges before your membrane. In this way you can easily recharge your resins and your membranes will last for years and years. I personally will pass on the anion resin as I don't believe we need it. The anion resin is used basically to extract the Na (produced by the ion exchange reaction of the cation resin) and the mebrane will have no problem handling it. Plus recharging anion resin is relatively dangerous unless you are well acquainted with the risks of handling HCL.

Merlin replacement filters and membranes as well as other components are still plentiful on the market so buy them when you can... our investment still has a good useful life to it.. don't despair spending money on another system which won't be worth the expense. Learn to care for your GE Merlin and your fish will be happy for years to come.

Some useful links:

Big Blue 4.5 X 20 inch housings:
http://www.ebay.com/itm/DUAL-BIG-BLUE-W ... 880wt_1102

Refillable cartridges with cation resin included:
http://www.ebay.com/itm/BIG-BLUE-4-5-X- ... 2914wt_901

The Big Blue GAC cartridge:
http://www.ebay.com/itm/BIG-BLUE-WATER- ... 2623wt_901

Merlin membrane set of two (best price):
http://www.amazon.com/Merlin-Membranes- ... 874&sr=8-2

And if you are interested in a new Merlin, I found this under the Hydrologics brand:

http://www.amazon.com/Hydro-logicTM-Mer ... 874&sr=8-1

Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 3:44 am 
Offline

Joined: Fri Dec 24, 2004 10:39 pm
Posts: 2955
Location: Toronto Canada
Ed,
For me with my 100 gpd RO unit, the membrane gets old within a few
months. Running some hot water in with the cold so that it is warm to the touch, makes it perform for a bit longer. I've never had a pump to circulate acid water through the system. The whole RO production thing is a painfully slow process and and takes longer by the day until I replace the membrane.

Merlin sounds terrific. Glad to hear you're on-track for keeping that baby operational.
D


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 4:00 am 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
The Merlin (and the new Evolution) are a very nice investment for us that we work with these blackwater species, and they cut your r/o water changes to minutes vs. hours depending on your usage. Plus the r/o water is great for preparing a good brewed coffee or tea, it brings the flavor out in a really nice way. Even wild betta species appreciated very much the soft and acid water (while I bred them).

To help out your 100GPD system, a softening system like I describe will make your membrane last at least a couple of years... though you can get great results from a smaller 2.5 X 10 inch housing prefilter system. They also sell the cation cartridges for that size of a housing. It's all really easy to install. I know your 100GPD membrane runs for around 35 bucks, but if you install the resin cartridge before the membrane, you'll probably be spending on a new membrane every 2-3 years. And the resin, you'll regenerate every few months or more in between recharges... cheap, plain salt is all you need.

Do you remember that thread we discussed several years ago, about the polishing before or after the membrane? Well, with the price of these Merlin and Evolution membranes, it's more applicable than ever.

Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 3:11 pm 
Offline
Administrator

Joined: Sat May 09, 2009 12:49 am
Posts: 469
Location: Las Vegas,NV
Great information Ed. Looking forward to seeing the numbers. Seriously considering doing this myself.


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 6:38 pm 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
Hi Mike,
The numbers you can get off the links, but you ought to check out locally at places that sell residential and commercial water filtration systems. I spent around 150 on the BB housings and refillable cation cartridge and carbon block, the Merlin membranes were a separate purchase.
Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 8:32 pm 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
BTW, you have the Pentek Big Blue housings and you have a generic Chinese made housing. I purchased the latter for 36.00 a piece. Just make sure they are the 4.5 X 20 inch housings.
Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Mon Mar 05, 2012 10:17 pm 
Offline
Administrator

Joined: Sat May 09, 2009 12:49 am
Posts: 469
Location: Las Vegas,NV
Ed,
I was referring to the tds creep. I would like to know if this actually works before I install new membranes. These last ones are just over a year old and are putting out 200tds water. It would be heaven to not have to replace them every year. It's such a waste of $$$. Where did you find the generic housings?


Top
 Profile  
 
PostPosted: Wed Mar 07, 2012 9:21 pm 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
Mike, what produces TDS creep is the residual concentration of carbonate salts in the r/o membrane. In other words, if the tapwater is not treated to soften it before hitting the membrane, the membrane will absorb all these minerals (and that is what the membrane is made for), and sooner or later (depending on the TDS of your tapwater source) these minerals will saturate the membrane (cause mineral fouling) and partially plug it and it may come to the point that the carbonates begin to be released by the membrane into the product water, thus you will get higher TDS readings. 200ppm from a r/o membrane means that it is functionally dead.

When we place the cation cartidge before the membranes, the resin will absorb all the hardenig minerals by exchanging them with a softer one, in this case, sodium. The cation resin is charged with sodium ions and its design allows it to absorb the calcium/magnesium ions and release the sodium ions... it exchanges one for the other.

The sodium ion is easily absorbed and managed by the membranes and are easily flushed out during membrane maintenance flush (which we have discussed). Merlin membranes can go for years without even need of flushing when prefiltered as I suggest.

Then, the cation resin can be regenerated (by recharging it in a salt water solution which will re-swap the Ca/Mg for new Na from the Salt (NaCl).

So if you take care of the resin with eventual recharging in salt water, you most likely will not be buying any more resin for many years, and so will your membranes last much more than you read in the books.

Rest assured these are facts Mike... the only thing new for me was to improvise a water softening system that would fit under my sink... a point of use water softening system.

You know a regular whole house water softening system requires at minimum 6 sq. feet of space. My design requires only 2 sq. ft. and a 24 inch height under the cabinet, compared to 48-72 inches height of residential whole house resin tanks.

Hope this answers your question

Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 1:01 am 
Offline
Administrator

Joined: Sat May 09, 2009 12:49 am
Posts: 469
Location: Las Vegas,NV
This more than answers my questions Ed. Thanks so much for starting this thread. You know how much room I'm working with. I thought there was no hope for my system. This is perfect.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 8:23 am 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
Setup a diagram of what I have. I will try to post some pics when I can... as soon as Merlin sump o-rings arrive when I will replace them. Click on the illustration and you can open it on your screen to see it larger.


You do not have the required permissions to view the files attached to this post.

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 9:04 am 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
Supplies at hand for the project (and of course the main items above):

* 1 inch male to 1/2 inch female reduction adapter.

* Watts PL-3036 Push Male Adapter, 1/2-Inch x 1/2-Inch (please take a small length of the Merlin tapwater feed tubing with you to Home Depot to make sure of the exact measure, as it could be the PL-3035 we may need, which is 3/8 OD on the push side). Don't buy it at Amazon, it costs half as much or less at HD. Buy two of these.

* Brass or PVC 1 x 1 inch male nipple adapter.

...and a roll of teflon!


You do not have the required permissions to view the files attached to this post.

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 9:16 am 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
It would be neat to install a 4.5 X 10 or 4.5 X 20 housing before above setup and place a high flow 1 micron sediment filter... but I'm good with what I have. Now let's see what the fish have to say!

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 12:31 pm 
Offline
Administrator

Joined: Sat May 09, 2009 12:49 am
Posts: 469
Location: Las Vegas,NV
You are saving me hours at home depot or Lowe's in the plumbing section staring at fittings. THANK YOU. I'm confused on the high flow 1 micron...would you install it in line after the big blue 5 micron?


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 4:54 pm 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
Really it is not necessary and I have not installed it (yet). This would become the very first stage and it is meant to polish very small particles (down to 1 micron) from tapwater and help keep the rest of the stages cleaner... every thing would just last more. Some of the 1 micron filters are reusable (you can clean them with a high pressure water hose or bleach) some are disposable, you have them made of melted plastic and you have them pleated, I have not looked into any specific cartridge for this purpose yet. Mostly, it will bring a little more peace of mind, but as the design is setup in the diagram, you really won't need to worry about getting new membranes if you follow your resin regeneration schedule.
Ed

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
PostPosted: Thu Mar 08, 2012 5:00 pm 
Offline
Administrator
User avatar

Joined: Sat Sep 17, 2005 3:21 am
Posts: 4239
Location: Salt Lake City, Utah
And while you're at it, you may want to replace the Merlin sump o-rings and check the fitting o-rings and condition. I purchased the 3 o-rings and the lock bar and fittings set new. You may not need all this, but my Merlin once flew in the air almost 30 feet and the manifold cracked after my acrylic 125 exploded 2 years ago and the water crash flooded everything in its way.
The manifold only suffered on the outside, valves kept working.

_________________
God listens. He may not always give you everything you want, when you want it; but he always gives you what you really need, when you need it most!
E.R.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next

All times are UTC - 8 hours



Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group

 

 
 

Species Identification Guide


Domestic Angelfish Genetics


Angelfish Chronicles


Members Galleries


 
Contact: Forum Administration
E-mail: info@finarama.com
Finarama.com
Dedicated to further understanding the Genus Pterophyllum