RODI water has more PO4 than my DT

seth the wine guy

seth the wine guy

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When was the last time you tested your RODI water? Mine is .05 using a Hanna bench top photometer. I changed every filter and bladder on my RODI unit thinking it was failing me. Still tested .05. So, I bought a booster pump thinking I wasn't pushing the water through the unit at the optimal PSI. Still .05. My DT is down to .02 using Phosguard. It's a shame that when I do a WC I'm actually raising my phosphates. I'm about to start running GFO on my RODI water. It's kinda sad.
 
What is your TDS reading?

Might be time for a new membrane or DI resin.
 
TDS is zero using 3 different meters.

Brand new 5 stage unit. Same reading as the old 4 stage.

Have you ever measured your RODI PO4 using a good photometer Colin? Might surprise you.
 
I was reading phosphates in my RODI with a hanna checker. When I contacted Hanna they told me that the test will only work with saltwater. Don't know if that would apply to the benchtop meter or not.
 
I have a pinpoint marine conductivity meter (water hardness) I guess is giving me good readings of RODI purity water
 
My TDS on the BRS 5 stage read 1 coming out of DI. PO4 read .16!! Holy ****.

I just replaced all filters and resin. We'll see tonight how it is.
 
Are you guys just testing the RO/DI water prior to mixing Salt? May have to check this myself, as I've only had my RO/DI unit for a couple of months. Since I have seen small amounts of GHA (which my Turbo Snails take care of rather quickly) I'm wondering if this is what is causing it to show. I did remove my Carbon bags and put some Phosguard in last week. So need to take a reading tonight and see how that is working.
Was really kind of hard to figure out the ppm as the colors are kind of close on the color match card. I think I am going to change the type of Test Kits and start going with the Seachem cases like my Mag test.
 
spankdog;794401 wrote: I was reading phosphates in my RODI with a hanna checker. When I contacted Hanna they told me that the test will only work with saltwater. Don't know if that would apply to the benchtop meter or not.
Click to expand...

Bench top can do all water.

The HI 93713 meter measures phosphate (PO43–) content in water, wastewater and seawater in the 0.00 to 2.50 mg/L (ppm) range.
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From the manual
 
Seth The Wine Guy;794393 wrote: TDS is zero using 3 different meters.

Brand new 5 stage unit. Same reading as the old 4 stage.

Have you ever measured your RODI PO4 using a good photometer Colin? Might surprise you.
Click to expand...

Never with a bench top one a hanna checker said 0. But apparently they don't do fresh water so I don't know.

I've always been under the assumption that zero tds meant that nothing was in there but hydrogen and oxygen.
 
MC524;794477 wrote: Are you guys just testing the RO/DI water prior to mixing Salt? May have to check this myself, as I've only had my RO/DI unit for a couple of months. Since I have seen small amounts of GHA (which my Turbo Snails take care of rather quickly) I'm wondering if this is what is causing it to show. I did remove my Carbon bags and put some Phosguard in last week. So need to take a reading tonight and see how that is working.
Was really kind of hard to figure out the ppm as the colors are kind of close on the color match card. I think I am going to change the type of Test Kits and start going with the Seachem cases like my Mag test.
Click to expand...

I have tested both RODI and SW mix.
FWIW- I don't think test kits for PO4 are precise or accurate enough for readings at the low range. They just give you a general idea more than anything.

Edit:
Mockery;794480 wrote: Never with a bench top one a hanna checker said 0. But apparently they don't do fresh water so I don't know.

I've always been under the assumption that zero tds meant that nothing was in there but hydrogen and oxygen.
Click to expand...

If all you have access to is the pocket checker you can at least measure your pre mix salt. I have gotten .01-.03 higher after adding salt.
 
I use the API test kits. I've always wondered about the accuracy of them. So the last Test Kit I bought was SeaChem Mag. test in the white plastic box. They are a lot more money, and take longer to test, but I think they are more accurate.
My API Phosphate test color match card is hard to judge. There are 3 colors that are not a whole lot different. However, the difference between the numbers for those colors is quite important.
I've tested my water, then brought a bag to one of my LFS to have them check. They have came back with low amounts of Nitrate or Nitrite don't remember which one. Where my test at home showed 0.
I think I'm going to start investing in the better test kits, I'd rather invest a little more and go with Hand Held Testers. Only problem with them is getting Calibration Fluids for them.
 
quick google search on that meter variance.....The meter has a margin of error of + or - 0.04. IF that's true, you could be closer to 0.
 
Oz;794509 wrote: quick google search on that meter variance.....The meter has a margin of error of + or - 0.04. IF that's true, you could be closer to 0.
Click to expand...

I wondered about my meter and it's accuracy. I had Dylan bring his same unit over and tested mine and his side by side. Both units read the same.

Regardless of variance, if my tank is consistently measuring .02 and RODI is .05 then it's pretty safe to say that PO4 exits at higher levels in the RODI.
 
I know your unit measures both Salt and regular but speaking from experience test it once you made your salt mix.
 
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