Hanna ULR 1774 Tap Water/RO/DI Readings

[Mikedawg]

I live in metropolitan ATL and my Hanna ULR 1774 (the newest model) gives me readings of phosphate levels in tap water of .13 consistently. I haven't been able to find the "official" Dekalb county water system levels of phosphate.

I am very careful to follow Hanna testing protocols. My BRS 5 Stage Plus RO/DI unit produces water with a phosphate reading of .08 and 0 tds, and I have recently changed the sediment filter and carbon blocks; the membrane is about 3 years old but I only make about 10 gallons a week. So, three questions:

Do these tap water readings seem "reasonable" compared with those of other urban water systems, and, secondly, will replacing the membrane on my RO/DI unit produce phosphate levels closer to 0? I haven't been able to find much research on what the membrane actually removes. Finally, could this be a calibration error in my device?

Thanks much for your help.

 

[lapin]

RO/DI with Phosphates but 0 TDS

I am getting around .05ppm P04 in my RO/DI as it comes out of the line but has 0 TDS. I am using a BRS 75gpd 5 stage RO/DI. The unit is 2 years old and I replaced the DI resin yesterday, but the carbon blocks are 2 years old and so is the RO membrane. I should say that I had this in storage (with...

www.nano-reef.com

 

[Mikedawg]

RO/DI with Phosphates but 0 TDS

I am getting around .05ppm P04 in my RO/DI as it comes out of the line but has 0 TDS. I am using a BRS 75gpd 5 stage RO/DI. The unit is 2 years old and I replaced the DI resin yesterday, but the carbon blocks are 2 years old and so is the RO membrane. I should say that I had this in storage (with...

www.nano-reef.com

Thanks lapin, very helpful and gives me a good perspective for what to do next.