New RO/DI unit phosphate readings

[advanwoerden]

I just bought a new 5 stage RO/DI unit from BRS, and after running it for a couple hours (65 PSI, 0 TDS reading) tested the phosphates. I used the digital Hanna Checker, which is supposed to be accurate to .01PPM with +/- 0.04 variability. Here are my results:

RO/DI water: 0.10PPM
Newly mixed water with Tunze Reef Salt: 0.14PPM
Tank water: 0.15PPM
Tap water with no reagent: 0.01PPM

I'm disappointed with this reading - do you think my tester is off, or are the phosphates really that high? I ran out of reagent, so was unable to test my tap water for comparison...

 

[advanwoerden]

Got more reagent, tested my tap water and got 1.88PPM, tested again the RO/DI water (after running for another hour) and still got 0.10PPM!!!!! Just to be sure, I tested the water without using reagent again and got 0.00PPM.

So, either my RO/DI really does have phosphates or the calibration on the Hanna Checker is off. Any suggestions? Anyone with a reliable Hanna Checker (or other digital phosphate tester) I could borrow to test my RO/DI water? I don't want to have paid $200 for a RO/DI unit that still gives me significant phosphates, esp. when my tap water isn't that bad..

 

[piranhapat]

I going through same thing. Put new filters in Ro/Di and TDS reading was 00.0. Tested my main tank with Red sea Phoshate test and reading 00.8 and 00.6 either way in between. Tested New salt mix and Reading was same as main tank. So either test kit is off. I have no algae growth but did have cyano on sand bed. Don't know if that was from Bio Pellents which I removed. Alot less so going to get Hanna test to see way I stand too. This is driving me crazy too. Running GFO & carbon too.

 

[advanwoerden]

Yeah, makes no sense... Brought my water to the LFS and their Elos test kit read zero... Too bad you're so far, I would let you borrow my Hanna Checker

 

[ecvernon]

i have had the same issue with my ro/di. I have never solved it. I went as far as changing all filters and media brand new ones and still had phosphates in my water. In the end i just decided to live with it.t one of the most effective way to combat the phosphates is to use a good phosphate reactor and GFO. I am currently using BRS high capacity GFO in a nextreef shorty reactor and now i cannot get my phosphates to read over 0.00 on both of my hanna phosphate meters

 

[skene]

No matter what you do... You are not going to remove phosphates out of water.
The object is to reduce as much as you can.
Phosphates are in everything around you. Flakes, Pellets, Salt and household Dust.

 

[advanwoerden]

ecvernon- what kind of RO/DI unit do you have?

skene, I agree it's hard to get your phosphates to zero in your tank, but the pure RO/DI water right out of the filter should be next to zero- that's the whole purpose of the filter. It seems like a waste of $200 if it doesn't...

 

[skene]

No. The purpose of the RODI is to reduce particulates such as rust, lime, and chemicals from the water composition to give you a purer form of water.
That's why we use things like PhosBan, GFO and others to reduce phosphate even more.

If you would totally eliminate phos out of water... out of salt... out of foods... Fish, Coral and everything else in between would be stressed out. Control the phos once it's in your tank. You'll get a better nights sleep.

 

[NewfiDog]

Depends on the filters in the unit, like skene says it will not remove 100% of the phosphate some only remove up to 95% and some say up to 99%.