RO/DI questions

I just got an RO/DI system from bulk reef supply (about a week ago) and about 1/5 of the DI resin is already brown.  The TDS in hovers between 500-700, the RO out is about 30, and the DI out is 0.  How long does DI resin usually last in the Cedar Rapids/Iowa City area?  How often do you flush your RO membrane?  How often do you replace you sediment filters and carbon filters?  How often do you replace the RO membrane?  The way it's looking, I'll be replacing the DI every month!  The sediment and chloramine/carbon filters look like they should last about 6 months while I've read that the RO membrane should be replaced every year.  I'm just trying to get a handle on what's going on here.  I've heard of people going 4 months without replacing their DI resin.  I lose about 20 gallons of evap per week and do monthly 20% water changes. So that's about 1200 gallons a year.

 

I have the 75gpd. I think it's rated at 98% rejection. I really think it was a flush issue. I checked the TDS this morning and off the RO membrane it was around 80!! I did a 1 minute flush today and it went down to 15. Maybe I just need to flush it everyday... Good thing DI resin is pretty cheap.

 

I think if it's completely brown you should replace it. I guess I didn't realize how hard the water was here! I came home today and the TDS off the membrane was 110. Did a 5 minute flush and it's back down to 20. Maybe I should just store my make-up water in a giant bucket like I used to. Right now I have it running continuously through my level-loc.

 

Pressure is not an issue for me. The gauge is at 60 PSI when water isn't flowing, 50 when it is. I think this area just has extremely ****ty water so the RO membrane gets cashed quickly and has to be flushed regularly (like every 5 gallons...)

TDS meters are pretty cheap. Less than $30 at most places. The dual in line from bulkreefsupply is like $24 and the single is $20 or something like that.

 

Came home today and it was at 130 off of the RO and 1/4 of the resin is brown now. I flushed it again and have made 5 gallons of water with the TDS off of the RO at 12... I really think running it continuously throughout the day off of my level-loc clogs the membrane. I'm definitely going back to the bucket method.

 

Went back to the bucket method. Checked the TDS this morning just to be sure that solids weren't leaching through the membrane when there wasn't any flow and it's steady at 14 TDS off of the RO. Lesson learned. Don't run your water purification system all day long /DesktopModules/ActiveForums/themes/_default/emoticons/tongue.gif