Jump to content

Don't want to see ads? Become a subscribed member.

New membranes 140 ppm


Recommended Posts

Hi guys


Ive been reading these threads for a while now, found some answers for my questions, so i hope you can help me on this one.

I have a merlin 720gpd ro (the one thats discontinued), good couple of weeks ago tds started to go up, it went up to 100 ppm, so i bought 2 new membranes and new prefilter. After installing them, tds reads 140ppm, after running it for at least 10 hrs, its still 130 ppm.

I have changed membranes before with no problems at all, tds normally settled around .14, tap water is 300-350.

Now the membranes i ordered from thecleaningwarehouse as they had the cheapest deal: 120 for two +vat.

I read somewhere that these membranes have a 8 month shelf life, could it be that they tried to get rid of these before xmas?

I called them yesterday, a guy starts to tell me to check my resin, so im like no that has nothing to do with it, so he says Kevin is not in today he is the ro expert, try calling tomorrow.

I tried calling them today, line is not working, they are gone to holidays propably...

What do i do now? Has anyone ever got a refund on such an item?

My water pressure is low, 30psi, but 140 ppm is just ridiculous.

Link to comment

Well ive been searching around for a solution,

I realized the housing of the membranes wasnt fully screwed on, they were so tight i didnt wanna break them, but then i read somewhere that because of this waste water could get mixed with the pure water, so i took them apart. I dont have vaseline at hand, and the plumbing shop nearby is shut on sundays.. So had to improvise and used some lard from the fridge, surprisingly it worked well, they are completely screwed in now. Im running it for a while now to see if that was the problem.

I dont even know why we bought lard, anyway it came handy

Link to comment

Well, i ran water for an hour, tds went up to 220ppm (!), so I tried something else: took all membranes and prefilter out, put some bathroom cleaner solution (didnt have bleach) in the housing, and ran water for another ~30mins.

After that i took it apart (it smelled really clean :) ) and put back membranes and prefilter again, ran it for over 2 hours, and it is now on .45 ppm which is an improvement, but im not impressed, considering i spent 165 quid on it.

Now the problem is, as i mentioned, that thecleaningwarehouse is shut until first week of january, and im away until the 7th as well.

Do you think I have a case, after all this time will be gone? Or should i make my peace with 87% efficiency? (you might think on such low pressure i should, but i had .10 with new membranes before)

Link to comment

You need to flush membranes for a good 24 hours to get the chemicals off. But I always say flush for around 2 hours and live with the ppm. You will see it drop after a week or so.

Another problem you may have is the flow restrictor may have clogged up so not creating the required back pressure

Link to comment

Well I hope you are right, I don't see any other options than to carry on with it and hope that tds will go down.

I also hope that while i'm away for 2 weeks no algae or anything will grow on the membranes.


If the flow restrictor was clogged, wouldnt it cause less waste water output? I don't have problems with that - pure to waste is around 1:5 (i know i need a booster pump)

Link to comment

Don't want to see ads? Become a subscribed member.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Ad Blocker Detected

Please disable your ad blocker

Our forum relies on ads to pay for the servers and our time maintaining and running the forum.

Sadly running a forum like this is not free, and due to our popularity, we need servers that can handle the amount of traffic and resources our forum uses.


If you do not wish to see ads on our site, please consider supporting the forum with a membership subscription.