Is there something better than mixed bed DI resin? | BRStv Investigates

Adsjj

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Na no siporax at all. made sure I didn't have any signs of that in my tank. I have given the tank 100 litre water change over 2 days cleaning 60% of the sand as I had elevated sulphur and had noticed a few black patches of sand in some calm areas at the back so have remove this and given it a good clean in fresh RO water. new pod arrived so now have 4 stages on RO unit. goes Cation 7tds, Anion 1 tds, Mixed Bed 0 tds, Mixed Bed 0 tds, I would hope now I am removing a lot of the silicate from the RO water. fingers crossed. thanks for all you help and info though guys.
 

Felipebarile

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OIK, that's reasonable. Top off water is not the only source, but it can be a substantial one of the TDS rises above 0 ppm.

You do not use Siporax media, do you? Some report huge silica additions that they attribute to that material.
Hi doctor, accompanying some forums here from my country, I saw that some people have stopped using resins and are using Gfo (granular ferric oxide) and say they have not had any more problems with phosphate and silica and report that it lasts longer than the resins. Do you find this exchange interesting?
 

Randy Holmes-Farley

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Hi doctor, accompanying some forums here from my country, I saw that some people have stopped using resins and are using Gfo (granular ferric oxide) and say they have not had any more problems with phosphate and silica and report that it lasts longer than the resins. Do you find this exchange interesting?
That's a fine way to remove phosphate and silicate, but what about issues such as copper?
 

Felipebarile

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That's a fine way to remove phosphate and silicate, but what about issues such as copper?
I understood and I did not even remember that the tap water can come with even excess copper. so you better not take the risk.

Another question is in relation to a great configuration for the DI filter. I want to leave my water with excellent quality and I wanted your suggestion of which sequence of resins best suited to have this water with good quality and quantity.

I thought of:
option 1: 600gr cationic > 600gr anionic > 600gr mixed

I was also suggested:
anionic> mixed> mixed
 

Randy Holmes-Farley

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I understood and I did not even remember that the tap water can come with even excess copper. so you better not take the risk.

Another question is in relation to a great configuration for the DI filter. I want to leave my water with excellent quality and I wanted your suggestion of which sequence of resins best suited to have this water with good quality and quantity.

I thought of:
option 1: 600gr cationic > 600gr anionic > 600gr mixed

I was also suggested:
anionic> mixed> mixed
Both of those will make perfect water. There can be debate over what costs least, and that answer will vary with the nature of the water you use and how much CO2 may be in it (and what ratio is even in a mixed bed).
 
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Felipebarile

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Both of those will make perfect water. There can be debate over what costs least, and that answer will vary with the nature of the water you use and how much CO2 may be in it (and what ratio is even in a mixed bed).
What is the amount of CO2 that would be ideal or closer to the ideal?

if the value is lower than expected how would you place the resins? and if it is above ideal how would it look? or has no relationship?
 

yellrihs

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I just changed out all my filters (sed, carbon, and resin), and I'm following the BRS custom DI with Single Bed Anion, followed by Mixed Bed (Purple). I have the BRS 6-stage water saver 150gal.

My question pertains to the TDS meter readings:
1st stage (after RO membranes) - 2ppm
2nd stage (after Single Bed Anion) - 6ppm
3rd stage (after Mixed Bed Purple) - 0ppm

Any idea why the TDS jumps from 2 to 6 ppm? It only occurred after I replaced the DI resin as described. Is this normal for this configuration?
Looking for an answer to this question, however my TDS after the membrane is 8 then jumps to 35 TDS after the Anion and then 0 TDS after the 3rd stage mixed purple. Is it normal for the TDS to increase after the Anion?
 

Ryanbrs

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There no use in measuring tds after the just anion because it hasn’t removed anything. The resin has just exchanged negatively charged contaminants for hydroxides which many very well have a stronger electrical charge than whatever was in the water. Remember the tds meter isn’t really reading tds it’s estimating them by measuring the electrical charge of the water.

It’s only valuable to measure tds after both cation and anion stages or a mixed bed where the hydroxides and hydrogen from both resins have formed pure water.
 

yellrihs

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There no use in measuring tds after the just anion because it hasn’t removed anything. The resin has just exchanged negatively charged contaminants for hydroxides which many very well have a stronger electrical charge than whatever was in the water. Remember the tds meter isn’t really reading tds it’s estimating them by measuring the electrical charge of the water.

It’s only valuable to measure tds after both cation and anion stages or a mixed bed where the hydroxides and hydrogen from both resins have formed pure water.
Thank you!
 

balkin

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So does everyone here leave the RO/DI system under pressure? That is do you leave the water on to the system all the time?? I turn mine on and off as needed, does this cause any issues??
 
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So does everyone here leave the RO/DI system under pressure? That is do you leave the water on to the system all the time?? I turn mine on and off as needed, does this cause any issues??
I'd say that it really doesn't matter either way. Here at BRS our systems are always pressurized, while at home (since I was using the faucet diverter and not a direct connection to the water line) I turned the water off after making what I needed. :)
 

chipmunkofdoom2

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So does everyone here leave the RO/DI system under pressure? That is do you leave the water on to the system all the time?? I turn mine on and off as needed, does this cause any issues??
The pressure is not really that important, but keeping the membrane wet is. Drying out a TFC membrane after it has been used will ruin it. If you can prevent the water from draining out of the system when you depressurize it, then you don't need to keep your system pressurized. However, it's difficult to ensure that the membrane remains 100% submerged if you shut off the source water and don't block the output line(s). Leaving the system pressurized is a good way to ensure the membrane stays wet.
 

balkin

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I'd say that it really doesn't matter either way. Here at BRS our systems are always pressurized, while at home (since I was using the faucet diverter and not a direct connection to the water line) I turned the water off after making what I needed. :)
Thank you!
 

balkin

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The pressure is not really that important, but keeping the membrane wet is. Drying out a TFC membrane after it has been used will ruin it. If you can prevent the water from draining out of the system when you depressurize it, then you don't need to keep your system pressurized. However, it's difficult to ensure that the membrane remains 100% submerged if you shut off the source water and don't block the output line(s). Leaving the system pressurized is a good way to ensure the membrane stays wet.
That makes a lot of sense!!
 
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