R/O unit advice/help

[ReefKeep66]

Hello all, I'm not new to the hobby, but I'm new to ro units. I picked up a used 100gpd pure water club unit. Was making 0.00ppm tds water last night. Went to make water today and the tds of the product water was 70-80ppm. Removed all the filters and to me they look alright. Since I'm new to ro units I'll see you what guys think,first filter to supply water

Second,

and third

I went to check the membrane and couldn't get it out.

After I removed all the filters and put them back on I was getting around 20 -23ppm tds

Any advice? Thanks!

 

[MondoBongo]

sounds like maybe a seal is not seated properly or the water is otherwise leaking through. just for a sanity check, maybe try testing the tds going in, and then again coming out. but it seems like maybe something is not sealing properly. i would check carefully for leaks, cracks, or anything else that looks amiss.

my actual RO membrane can be a bit tricky to get out because it does tend to seal itself in there pretty well. if i recall correctly, i GENTLY used a pair of pliers to get a little more purchase on it to help liberate it the last time i changed filters. gently being the operative word there.

 

[ReefKeep66]

Doesn't appear to be any leaks. I have left it running for last 45 mins or so and the tds has dropped from 20 to 8 now? Should I leave it running?

 

[ReefKeep66]

Oh and tds coming in is around 50ppm

 

[Vinny Kreyling]

Looks like # 2 & 3 are in the wrong order.
1- water filter
2- carbon block
3 - DI

 

[ReefKeep66]

Ok a little update. I thought about it, there no visible leaks but I can hear what sounds like a suction noise maybe? Sounds like it's coming from the membrane. Product water tds is now 2ppm though.

 

[hkgar]

The first picture is a sediment filter and it looks dirt it should be white. This should be the first filter.
The second is the DI resin chamber and it should com the very last last. After the RO membrane.
The third is the carbon block and should be the second filter, after the sediment and just before the RO membrane.

Which line in the picture is your input line and which is the final out put line?

 

[ReefKeep66]

Red Is supply, blue is product, and clear is waster

 

[ReefKeep66]

I switched the di to the third and and the carbon block to the second.

 

[Vinny Kreyling]

I would suspect the suction noise is the membrane NOT being seated all the way.

 

[hkgar]

I switched the di to the third and and the carbon block to the second.

By third I hope you mean "after the RO membrane" and not before. DI is always the very, very last step.

 

[ReefKeep66]

There's 2 di I believe. Directly above the membrane.

 

[DDon]

There should not be a DI cartridge before the RO membrane. If before, resin is doing all the work and will be burned out rather quickly. The DI resin in the picture looks used up (very little blue). Your pre-filters will remove sediment and chlorine, both of which will damage your RO membrane. The RO then removes the majority of other contaminates and the DI resin then removes the ret so you end up with ultra pure water. With 50 TDS inlet water, you should see about 2 - 3 TDS out of RO then zero out of DI.
Hope this makes sense. And sorry your previous thread got so off track.

 

[ireef86]

It's always a good idea when purchasing a used rodi unit to replace filters. It's your tank that will endure any ill effects! I would even recommend replacing the TDS meter because they are subject to failure.