RODI help

[Octane13]

Hi all,


Looking for some help here. I was having some issues with some corals off and on, nitrate always maxed out my kits? Been carbon dosing and doing large water changes regulartly. Sent out a couple ICP recently they confirmed nitrates EXTREMELY high. First test was 147 and then 152. Currently running 7 stage RODI with 2 anion resins and a mixed bed. Still getting over 5ppm of nitrates fresh mixed water. Corals looking OK and growing now but still. Is this a mistake?

 

[LRT]

Hi all,


Looking for some help here. I was having some issues with some corals off and on, nitrate always maxed out my kits? Been carbon dosing and doing large water changes regulartly. Sent out a couple ICP recently they confirmed nitrates EXTREMELY high. First test was 147 and then 152. Currently running 7 stage RODI with 2 anion resins and a mixed bed. Still getting over 5ppm of nitrates fresh mixed water. Corals looking OK and growing now but still. Is this a mistake?

So your RODI water test came back 150ppm without being mixed with salt?
Why 2 Anion stages? Anion is the 1st resin to deplete in my RODI.
ID switch out Anion with Cation in 1st stage before Anion then mixed bed.

You tds should be 0. I run exact same setup. Start with 450-500ppm out of faucet to Sediment fliter>Pentek Chloramine filter>1 micron carbon block>Membrane>Cation>Anion>Mixed bed> Top off water at 0 tds.
Highly reccomend adding membrane flush. Only takes 30seconds to a minute to flush 300ppm water from my membrane before sending it to di resin and super savings on resin.

 

[Octane13]

So your RODI water test came back 150ppm without being mixed with salt?
Why 2 Anion stages? Anion is the 1st resin to deplete in my RODI.
ID switch out Anion with Cation in 1st stage before Anion then mixed bed.

You tds should be 0. I run exact same setup. Start with 450-500ppm out of faucet to Sediment fliter>Pentek Chloramine filter>1 micron carbon block>Membrane>Cation>Anion>Mixed bed> Top off water at 0 tds.
Highly reccomend adding membrane flush. Only takes 30seconds to a minute to flush 300ppm water from my membrane before sending it to di resin and super savings on resin.

Sorry for the confusion. My TDS is 0 and the nitrate numbers are off tank water. When I started to investigate i was getting roughly 17ppm in fresh mixed water (hanna diluted). When I first went from 4-7 stages it was below 5 for a couple rounds of water changes.

 

[LRT]

Sorry for the confusion. My TDS is 0 and the nitrate numbers are off tank water. When I started to investigate i was getting roughly 17ppm in fresh mixed water (hanna diluted). When I first went from 4-7 stages it was below 5 for a couple rounds of water changes.

I've never actually tested my fresh mixed water for Nitrates. I'll let someone else chime in that can make sense of that for you.
Id for sure switch out 1st anion stage with cation to make di resin stretch alot longer. Id imagine your tearing through it pretty fast.

 

[Octane13]

I've never actually tested my fresh mixed water for Nitrates. I'll let someone else chime in that can make sense of that for you.
Id for sure switch out 1st anion stage with cation to make di resin stretch alot longer. Id imagine your tearing through it pretty fast.

Whats strange is that it doesn't color change. I'm only running 2 as a test for lack of a better option.