Time to replace RODI filters.

It goes

WATER LINE > SEDIMENT > CARBON > MEMBRANE > CENTERLINE TO DI.
Pressure gauge is on the Carbon > membrane line aswell in a T fitting

Off-center to drain

Can I have a link just to be sure we're looking at the same product?

EDIT: Hmm..wait one second. Let me video this. I don't think we're on the same page.

 

SpectraPure Water Purification Products . The first system that pops up at the top of the page is the $125RO/DI-90 refurbished RO/DI I am speaking about. It is also the third item down the page in the January sales flyer.

The plumbing should be similar to this drawing minus the ASOV and pressure tank:
http://www.spectrapure.com/huds/4-STAGE-DWK-RODI-NAG.pdf

 

Heres the video

20130122_093253.mp4 video by kiddingdragn12 | Photobucket

 

It appears to be plumbed correctly. That has not solved your high TDS problems though.
How long does it take you to make 1 gallon of treated water? If the membrane is compromised or you have a cracked membrane housing it may make water faster than 75 GPD or about 3 gallons per hour at 77 degrees F and 50 psi. This could be another indication of a bad membrane or housing.

 

I think this is a 100 GPD system. It's a AquaFX Barracuda. I inspected the membrane housing and it was not cracked, externally or internally. I will order Spectras immediately.

 

The 100 GPD Dow Filmtec membrane is not a true RO membrane but should still be around 90% efficient vs 96-98% or higher for their 75 GPD version or the treated and tested Spectrapure membranes.