RO/DI Filter Replacement, Already?

So I got a RO/DI about two months ago. It's a 90 gallon spectra pure. If I had to guess how much water I've made I would say about 200-250 gallons. My tap water on the TDS is 212 and the RO/DI is showing 82...

Is it time to replace already? What's the highest TDS reading that would not harm fish or zoas?

 

What type of tds meter are you using? A reading of 82 after DI is hard to believe.It could be a meter malfuntion.

 

False alarm. The container I was putting the water in was contaminated. Filled up a cup and it tested out at zero. I was going to be ticked off if the filters needed replaced already....

 

ALWAYS measure directly from the RO membrane or DI filter when troubleshooting a RO/DI system.
You need three TDS readings, tap TDS, RO only TDS before the DI and final or RO/DI TDS. All three numbers are very important as you cannot calculate the rejection rate of the RO membrane, the workhorse of the system, without knowing the tap and RO only TDS numbers. This is often overlooked and when the RO membrane is not functioning correctly the DI resin must act as a crutch and prop it up, quickly exhausing the DI resin.

With the Spectrapure systems, make sure you take the couple minutes necessary to check and adjust the waste ratio by trimming the capillary tube which is one of the unique features that make their systems stand out. When you keep the waste ratio at the recommended rate and keep the sediment and carbon block filters servived with their suggested replacements it is not unheard of to see a Spectrapure RO membrane last 10 years or more. I am over 5 years on my present membrane and still at 99.4% RO rejection rate with a tap TDS over 600 so it is possible.

 

Anytime I see a post from ADR, I'm going to read it

(bowing, chanting, 'we're not worthy')

 

AZ knows his stuff and is always willing to help! Great guy full of info!!

 

Thanks for the insight! Very helpful!

AZ has been a huge help so far in this process. I'm grateful for his knowledge and willingness to help a newbie out.

 

Just doing what others have done for me. Thats what these forums are all about, sharing information and experiences both good and bad so others may not have to go through some of wha twe have in the past. I wish I had all the money I dumped on bad skimmers, pumps, RO filters, supplements and non reef friendly inhabitants!

 

That makes two of us on that one!

 

+1. AZ always brings great/reliable info to any thread. But, if your talking water and RODI, AZ is the MAN!