RO/DI pressure problems

[Tazmaniancowboy]

Just recently my pressure guage on my RO/DI dropped from it's normal 70-80 psi down to about 20-30psi and obviously my water production dropped drastically with this change. It was a pretty long time since my last filter change so I purchased all new filters and installed them. I had great pressure for that night and woke up the next morning to see that the pressure dropped to 40psi and then by the end of the day it was around 20psi???? I ruled out my booster pump being bad because the inline guage after it is pinned at 80psi but the guage at the membrane is the one that is dropped. I can not figure out what is happening here. The only thing I can think of is that my membrane is torn or has a hole and not producing back pressure. The only other thing I need to try is look at the waste to goo ratio and I will try to do that sometime this weekend.

Has anyone experienced this? is there anything else I should look at? I am going to need water DESPERATELY within a week and need to fix this asap!

 

[TanksNStuff]

First a question : Do you have any check valves or any type of valve between the pressure drop areas? Maybe you have a stuck valve or maybe a pinched tube somewhere?

Another possible issue: I know colder temps can cause slower rodi production. There's a way to fix that by running an extra long tube for the intake of the rodi, and coil it up in a 5g bucket. Then fill the bucket with water and put in a small (50w or so) heater to warm it up. With this method, the intake water gets warmed before entering the filter and helps reduce pressure drop.

 

[Fish Brain]

It sounds like there is a blockage between the booster pump and membrane. One of the pre-filters might have something clogging the passages or there is a kink in the tubing somewhere.

 

[magic]

Check the gauge itself to see if there's a blockage also.

Bob

 

[Hawkeye]

Another possible issue: I know colder temps can cause slower rodi production. There's a way to fix that by running an extra long tube for the intake of the rodi, and coil it up in a 5g bucket. Then fill the bucket with water and put in a small (50w or so) heater to warm it up. With this method, the intake water gets warmed before entering the filter and helps reduce pressure drop.

wow what a great idea - never thought of that.

 

[TanksNStuff]

I can't take credit for that one though Phil. I heard it from someone else on these forums a while ago (I think it was Sid?) and they provided a link to where they found the idea.

It is a great idea though.

 

[Tazmaniancowboy]

OK, so I just tracked my new problem down to the carbon blocks that I bought. My unit was set up with 2 carbon filters originally with different micron ratings. I could not get the exact replacements so I substituted 2 Matrikx solid carbon blocks on recommendation that others like them. After tracking pressures from the spigot through each chamber I found that very very little pressure was getting past the carbon blocks. I then eliminated one of them and the pressure after wnet from undetectable to 60psi immediately. After 30 mins it dropped to near 40psi. Is anybody using these solid carbon blocks? I just talked to another fellow reefer who said he had the same problem and never used them again. I wonder what pressure these need to be fed with?

 

[DeathMagnetic]

they have to be the correct micron rating.. i believe the first filter is 10 micron and the second is 5 micron... anything smaller would restrict the flow..

 

[Tazmaniancowboy]

Sorry to not respond sooner

Check the gauge itself to see if there's a blockage also.Bob

Thanks Bob, never actually thought of that. I now know it is working though

First a question : Do you have any check valves or any type of valve between the pressure drop areas? Maybe you have a stuck valve or maybe a pinched tube somewhere?Another possible issue: I know colder temps can cause slower rodi production. There's a way to fix that by running an extra long tube for the intake of the rodi, and coil it up in a 5g bucket. Then fill the bucket with water and put in a small (50w or so) heater to warm it up. With this method, the intake water gets warmed before entering the filter and helps reduce pressure drop.

Change in temp is undetectable to me George, I've been running this for 3 years this way. but thanks for the thoughts.

It sounds like there is a blockage between the booster pump and membrane. One of the pre-filters might have something clogging the passages or there is a kink in the tubing somewhere.

Thanks for the ideas also, No kinks, no valves, but definately a blockage!

 

[downbeach]

I only have a 4 stage, 75 GPH unit and use the 1 Micron MATRIKX +1 Carbon Block along with the 1 Micron ROsave.Zs sediment filter, without a problem. The unit originally came with the 5 micron version of these prefilters. My pressure gauge is connected just after the prefilters @ ~ 60 psi.

Could there be something caught between the filter canisters? Maybe run a small brush or pipe cleaner through them to make sure there is no obstruction.

 

[Tazmaniancowboy]

This carbon block has a rediculously small pore size of .6 Micron after looking it up. Going to run to Lowes and buy carbon filter there.

Sent from my HERO200 using Tapatalk

 

[TanksNStuff]

I'm using the same 1-micron Matrikx carbon and 1-micron RoSave filters that Jim mentioned and I don't have any issues. I don't have a pressure gauge nor any kind of booster pump... just hooked right up to my hose tap in the garage... but it flows just fine for me.