Cryptic problem: RO membranes clog up. Please help

[Buckeye Hydro]

What problem are you trying to address with the soda ash? Trying to increase the pH of the feedwater without increasing hardness? Are you dosing the soda ash too much?

Also - you bought an RO system that uses encapsulated, proprietary filters. Ugh. Not what we would have recommended.

 

[Cobra1365]

What problem are you trying to address with the soda ash? Trying to increase the pH of the feedwater without increasing hardness? Are you dosing the soda ash too much?

Yes, trying to raise Ph. I’m getting a new water test today from Dept of Nat Resources. Last test did not indicate hard water. Just low Ph and nitrates. Hence soda ash and RO.
Crazy thing is this just started around Feb. It‘s been operating fine for ~2 yrs.

 

[Cobra1365]

Also - you bought an RO system that uses encapsulated, proprietary filters. Ugh. Not what we would have recommended.

Yes, I’m finding that out!

 

[Buckeye Hydro]

Sounds like your dosing the soda ash at too high a rate

 

[Cobra1365]

Sounds like your dosing the soda ash at too high a rate

Ok, now I’m confused. If the water is at a Ph of 6, with 7 being ideal, wouldn’t I want to increase soda ash to raise Ph?

 

[rajdude]

At the risk of hijacking your thread…
I’ve read entry run into a situation with my drinking water RO system. The pre filters clog within a month and the system stop producing. I cut open a pre filter yesterday and it was coated with a white slime that looked like silicone grease.
I already have a 5 micron spin down, a 10 micron sediment and a carbon block all BEFORE the RO system. None of which show any slime build up.
From those three filters, the water flows into a soda ash system which consists of a 15 gallon tank where the soda ash mixes with water and is drawn from By a stunner pump activated by useage demand. Then it goes to a holding tank Where it mixes with household water.
1) What would that slime be?
2) Why only on the RO system
3) is there something I could add to the Soda Ash tank to eliminate it?

BTW, MY RO system is an ECO Water 375 and has sealed filter canisters. So, no way to do periodic cleaning other than replace filters at $70 a pop!

Well, you may want to start a new thread about your problem. It is very different than what is being discussed in this thread (you got pre-filter clogging issues. This thread is about RO membrane clogging issues).

Having said that, it is pretty easy and cheap to swap out your sealed canister filters to replaceable filters. All you need is a housing and a filter (or two). Many vendors will sell you a kit with two housings and two sediment filters. Then changing sediment filter becomes a 10 dollar or less expense.

BTW, judging from how this problem started recently, it seems to me that your water company may have started dosing something new into your water. Call and ask them. I did that and they were pretty helpful.

 

[rajdude]

ok folks, here is an update about my problem:

Short story:

The problem seems to have been fixed by adding a booster pump. YES! It was as simple as that

Long story:

The house water pressure, which reads at around 70 PSI may not be enough in my particular water situation, whatever that is. At the time of adding it (November 2022) the booster pump was running at around 85 PSI. Today it is reading around 90 PSI. I guess that is due to the 2 membranes getting a little clogged. Time for another acid bath?

Here is something which is really interesting:

From mid December 2022 onwards, I stopped dosing the descalant and flushing. I had to go out of the country for a few weeks, and my lovely wife balked at the complexity of operating my “water treatment plant” LoL but she agreed to change water in my fish tank (mostly automated). So, I did two things before going:

1. I hooked up a simple auto shut off solenoid valve into the RO system, which stopped the booster pump when the 2 drums were full (they have float valves).
2. I left the auto flush valve alone, because I did not have enough controllers. So no flushing was happening like I was doing manually, daily.

When I came back I noticed that the system was working fine, still producing RO water at the same speed as earlier. TDS was still good (around 4). So I thought, lets see for how long this runs without clogging.

Well, almost 8 months have passed, I have not touched my “water treatment plant”. It still is working fine. TDS is still 4.

Hence my observations are (for my particular situation):

• All I needed is high pressure at the RO membranes to seemingly overcome whatever I have in my water (which was clogging my RO membranes in the past).
• Flushing before and after RO water production seems to have no effect. I guess it is a waste of time and water.
• No need to dose anti-scalent
• It is probably time for maintenance: change pre-filters and acid bath the membranes to clean them.

Note:

I am using two membranes. It is the BRS kit.
Of course now I have jinxed it! It will fail tomorrow ;-)