PO4 in RO/DI

[Sindjin]

Check this out...

I did my weekly water change yesterday. Tonight, my PO4 tests .05ppm.

Guess what?

I just tested my FRESH batch of RO/DI I made for top-off...
It tested 0.1ppm. Whats up with that? I am actually ADDING PO4 to my system and my system is then exporting it!

I just replaced the cartridges and DI resin 3 weeks ago.

Any suggestions?
Anyone else have this problem?

 

[Weatherman]

Re: PO4 in RO/DI

<a href=showthread.php?s=&postid=6540308#post6540308 target=_blank>Originally posted</a> by Sindjin
Check this out...

I did my weekly water change yesterday. Tonight, my PO4 tests .05ppm.

Guess what?

I just tested my FRESH batch of RO/DI I made for top-off...
It tested 0.1ppm. Whats up with that? I am actually ADDING PO4 to my system and my system is then exporting it!

I just replaced the cartridges and DI resin 3 weeks ago.

Any suggestions?
Anyone else have this problem?

How long has it been since you've replaced the RO membrane?

 

[Sindjin]

I havent. It said one year. So I figured I could go 6 months...

I started using the unit in October.
Should I? How often, then?

 

[Weatherman]

<a href=showthread.php?s=&postid=6540337#post6540337 target=_blank>Originally posted</a> by Sindjin
I havent. It said one year. So I figured I could go 6 months...

I started using the unit in October.
Should I?

A good RO membrane shouldn't get clogged up that fast, unless your source water is just packed full of stuff.

Tap water in South Florida runs about 250 ppm TDS. The membrane on my RO/DI unit (an Air, Water and Ice Typhoon III), lasted about two years before showing signs of problems.

A sure sign your RO membrane is failing is when you rip through DI cartridges in record time (like, maybe, two or three weeks). Your RO/DI output should have a TDS of zero (or maybe 1 ppm).

I've never paid much attention to the phosphate level in my RO/DI water. I always mix Ca(OH)2 into the water, so I figure whatever phosphate there is will rapidly precipitate out.

 

[Sindjin]

I need a TDS Meter.
My old one disappeared years ago.

Check your PO4 before adding it to your system. Id be curious.

 

[Weatherman]

I just ran a Salifert test on a batch of RO/DI water I made a couple days ago.

The test water remained clear.


My RO membrane is about a month old (just replaced after 2 1/2 years). The DI cartridge is about 3 months old, and the other filters are about six months old.

TDS is 0.

 

[javajaws]

When you get a TDS meter, try to get a reading right out of the RO without going through the DI. If your unit doesn't have an RO only valve, just unhook the line.

How much have you run though the DI since you changed it? Maybe you haven't run enough water through to get the DI to run clean water yet (usually takes a couple gallons).

 

[Sindjin]

Weatherman,

Wow...it sounds like you have things nice and clean! Im going to change my membrane I guess. In the first 3 months, I was changeing TONS of water becuase I was Curing my UNCURED live rock. I may have put my unit into overdrive. (heh...I havent said that since before I was married!)

Javajaws,

I have run about 60 gallons thru the new resin so far.
Im gonna go to the LFS and check prices on a TDS Meter and membrane.