Phosphates in RODI - Hanna ULR Correct?

[Djbetterly]

So I've been struggling a bit to figure out if my hanna ULR meter is working correctly. Every time I test my tank water I get 200, not 199, not 201 - 200. I ran 7 tests yesterday, 200 every time.

This morning I tested my RODI water to see and I got .032. All of the filters, membranes and DI were replaced about a month ago.

The reason I find this odd is because with the original batch of reagents I had, I always had to do about 5 tests and then average them because of how much the tests swayed.

What is your experience? Thoughts?

Hanna is sending me new reagents, so maybe they suspect this to be odd as well.

 

[PhoenixOne]

You're referring to the Hanna Checker right? If so, I've read that some get erratic results using the Hanna Checker. I myself rarely get erratic wide range results. They're usually between 0.00 to 0.03 range. I was also told that I should invest in the Hanna Phosphate Meter (the expensive $200+ one) because it is way more accurate.

I'm a bit confused, what do you mean when you say "I get 200, not 199, not 201 - 200"?

 

[greg 45]

It is still possible that the ro // di isn't working
I have exhausted cartridges faster in the winter anmd I have 3 di
Check water out of tap and compare to water out of ro /di
I had 40 ppm when my cartridges went bad , chased hair algae 4 a while after that issue , hope this helps

 

[Djbetterly]

@PhoenixOne, I get exactly 200ppb every time, nothing different.

@greg_45, I will give the tap a shot. My TDS meter reads zero on the output though. Not sure if that means anything in terms of PO4.

 

[Djbetterly]

So I think I may have discovered the issue..The range of the meter only goes to 200ppb.

Tap Water > 200ppb
RODI .03
Tank Reading >200ppb

Is it common for new tanks to have high PO4? I haven't gotten my reactor up and running yet. Guess I should. Clearly the fuge hasn't taken hold yet having only been up and running for a week.

 

[greg 45]

good to know the ro / di is working i always check there first
i dont always trust tds number / mine read 0 tds with the high po4 number

 

[Djbetterly]

Well I'm convinced that my high PO4 is a product of my tank being very new as well as from me using dry/dead rock. I bought the rock from Marco Rocks, but that doesn't mean it isn't going to leach at all. In the mean time I'm going to continue skimming wet, and do a lot of water changes.