Phosphate reading from RODI water?

[ERIC1975]

So out of curiosity I tested my RODI water today for phosphate since I can't never get my DT water to go below 0.04 phosphate readings. I have the 4 stage BRS RODI unit. Membrane/carbon block and DI resin are all good and the the built-in TDS meter says 11ppm coming out of the membrane and 0 ppm coming out of the DI resin. So you would assumed you would get 0 reading for phosphate? BUT it's 0.07!!! What the hell?
The water I tested is coming straight out out the RODI unit and has not been in contact with any container. I used Hanna test kit Any idea how this is possible and how do fix it? Thanks guys!

 

[SchnitzelReef]

So out of curiosity I tested my RODI water today for phosphate since I can't never get my DT water to go below 0.04 phosphate readings. I have the 4 stage BRS RODI unit. Membrane/carbon block and DI resin are all good and the the built-in TDS meter says 11ppm coming out of the membrane and 0 ppm coming out of the DI resin. So you would assumed you would get 0 reading for phosphate? BUT it's 0.07!!! What the hell?
The water I tested is coming straight out out the RODI unit and has not been in contact with any container. I used Hanna test kit Any idea how this is possible and how do fix it? Thanks guys!

What did u test it with? There's usually a +/- percent that it could be wrong. Read the box


Hot Dogs are GOOD!

 

[Six2seven]

if your display tank is reading 0.04, I would stress on it too much. if you're having problems with your tank I would look elsewhere before you come back to this

 

[ERIC1975]

if your display tank is reading 0.04, I would stress on it too much. if you're having problems with your tank I would look elsewhere before you come back to this

My display reading fluctuates between 0.04 and 0.10. I used hannah test kit which is supposed to be good? I just thought RODI water supposed to have 0 phosphate if the TDS is reading 0ppm? or no?

 

[theweaz]

What's your TDS reading? I would trust that more than the hanna kit.

 

[Emac909]

I've been saying this for years guys. I live in Yucaipa. My water source is 85% well water witch is high in silica. So I have a 7 stage ro/di system. 1 sed, 3 carbon, 1 ro, and 2 di. I'm getting 0 TDS out of my filter but still get 0.08 po4 straight out of the filter. I test it b4 it can hit a container. Ro filters do a lousy job on removing silica. Silica reads as po4. To eliminate the phosphates u need to replace the di with a silica buster filter.

 

[ERIC1975]

I've been saying this for years guys. I live in Yucaipa. My water source is 85% well water witch is high in silica. So I have a 7 stage ro/di system. 1 sed, 3 carbon, 1 ro, and 2 di. I'm getting 0 TDS out of my filter but still get 0.08 po4 straight out of the filter. I test it b4 it can hit a container. Ro filters do a lousy job on removing silica. Silica reads as po4. To eliminate the phosphates u need to replace the di with a silica buster filter.

I'm in Elsinore...not sure where the water is from...maybe from the lake? probably no well water. so that means my phosphate reading could be false? At first I thought it was the container leaking stuffs into the water but when I tested straight out of the filter and still get 0.07ppm.

 

[Emac909]

If your water source is a natural source then most likely it's silica. Cities that Recycle and purify their use kalk to do so. Kalk is a really good way to strip the water of silicates.

 

[DonGil]

Was following this thread because I've got the same problem. Phospahtes were high in My DT & Frag tank. Readings 0.12. So I installed a Spectrapure Silica buster cartridge in my RO unit. Ran 15 gallons of water through it and my phospahte reads 0.07 now. So Im thinking maybe my container is leaching phospates. I get a reading of 0.05 coming directly out of RO unit. Is this an acceptable level? It still seems high to me. Im testing with a Hanna ULR.