marduc
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Is all DI resin created equal?
- Thread starter virginiadiver69
- Start date
virginiadiver69
New member
What amount would constitute a high co2?
Rat
Don't mean to "gang-up" up on you but as I have said before your own guy Charles Mitsis from Spectrapure disagrees with you. As has also been pointed out IIRC a std 10 x 2.5 inch cartridge holds 20 oz of resin rather than 24 oz. You keep going by 24 oz which is 15 % less resin.
Repeatedly I have asked you for your pH and Alk of your tap water but you do not seem to want to give it, which will resolve the issue on your tap water and DI resin depletion in relation to CO2.
Form a file I made from a copy paste from an old thread by Charles form Spectrapure about a year ago
4.) When speaking of resin capacity, the MaxCap DI cartridge has a total capacity of approx. 18,000 ppm-gallons, vs. about 6000 ppm-gallons for a high-quality mixed-bed cartridge of 700 ml volume (the typical 24 oz. screw-on DI shell). When calculating the approximate gallons a DI cartridge will process, one must account for the total ionic load, both cationic and anionic, presented to the resin cartridge â€"œ not just the TDS reading. The presence of CO2 can be a huge factor that must be added to the TDS reading of the water presented to the DI cartridge. Many times the CO2 can be far in excess to the TDS reading.
5.) To calculate the effects of CO2 on DI production, divide the CO2 product water concentration in ppm by the sum of the CO2 concentration in ppm plus the product water TDS in ppm. For example, if you have 4 ppm TDS and 4 ppm CO2 in your RO water, you are wasting 4/8 or 50% of your anionic DI capacity on CO2 removal.
For those wanting to know the relationship of CO2 - Alk - pH here is a table. Pay no attention to the green line which is the sought level in FW planted aquariums.
And here is a CO2 calulator for FW, also with another table at the bottom.
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm
To add these tables are for pure water. As the conductivity or TDS of the water increases there is a shift in the pk1 and pK2, which will shift the pH and thus CO2 concentration. Meaning, a TDS of 100 ppm, pH 7 and Alk 5 dKH, will not have the same amount of CO2 as TDS of 1 ppm, at the same pH and Alk. Meaning, you would need a different table or calculator but for any of our purposes in RO water or even most FW tanks they are close enough.
Don't mean to "gang-up" up on you but as I have said before your own guy Charles Mitsis from Spectrapure disagrees with you. As has also been pointed out IIRC a std 10 x 2.5 inch cartridge holds 20 oz of resin rather than 24 oz. You keep going by 24 oz which is 15 % less resin.
Repeatedly I have asked you for your pH and Alk of your tap water but you do not seem to want to give it, which will resolve the issue on your tap water and DI resin depletion in relation to CO2.
Form a file I made from a copy paste from an old thread by Charles form Spectrapure about a year ago
4.) When speaking of resin capacity, the MaxCap DI cartridge has a total capacity of approx. 18,000 ppm-gallons, vs. about 6000 ppm-gallons for a high-quality mixed-bed cartridge of 700 ml volume (the typical 24 oz. screw-on DI shell). When calculating the approximate gallons a DI cartridge will process, one must account for the total ionic load, both cationic and anionic, presented to the resin cartridge â€"œ not just the TDS reading. The presence of CO2 can be a huge factor that must be added to the TDS reading of the water presented to the DI cartridge. Many times the CO2 can be far in excess to the TDS reading.
5.) To calculate the effects of CO2 on DI production, divide the CO2 product water concentration in ppm by the sum of the CO2 concentration in ppm plus the product water TDS in ppm. For example, if you have 4 ppm TDS and 4 ppm CO2 in your RO water, you are wasting 4/8 or 50% of your anionic DI capacity on CO2 removal.
For those wanting to know the relationship of CO2 - Alk - pH here is a table. Pay no attention to the green line which is the sought level in FW planted aquariums.
And here is a CO2 calulator for FW, also with another table at the bottom.
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm
To add these tables are for pure water. As the conductivity or TDS of the water increases there is a shift in the pk1 and pK2, which will shift the pH and thus CO2 concentration. Meaning, a TDS of 100 ppm, pH 7 and Alk 5 dKH, will not have the same amount of CO2 as TDS of 1 ppm, at the same pH and Alk. Meaning, you would need a different table or calculator but for any of our purposes in RO water or even most FW tanks they are close enough.
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virginiadiver69
What amount would constitute a high co2?
Just measure the pH and Alk for the RO water (not the DI water). Normally a low pH or a high Alk means high CO2. You need to know the Alk more than anything. In Dick and Jane terms think of it like this;
CO2 = pH / Alk
Which also means
pH = CO2/ Alk and Alk = pH x CO2
But the actual equation is much more complex than this.
Also virginiadiver69 I should add a Water Softener will do about nothing for high CO2 or even high ALK. If these two are not an issue and your RO still has high output water and the DI is still depleting due high concentrations of other ions that are making it through the RO, then a WS will help.
What amount would constitute a high co2?
Just measure the pH and Alk for the RO water (not the DI water). Normally a low pH or a high Alk means high CO2. You need to know the Alk more than anything. In Dick and Jane terms think of it like this;
CO2 = pH / Alk
Which also means
pH = CO2/ Alk and Alk = pH x CO2
But the actual equation is much more complex than this.
Also virginiadiver69 I should add a Water Softener will do about nothing for high CO2 or even high ALK. If these two are not an issue and your RO still has high output water and the DI is still depleting due high concentrations of other ions that are making it through the RO, then a WS will help.
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AZDesertRat
In Memoriam
I already told you my pH is 8.2. Alkalinity averages 120 to 150 depending on the source blend and the time.
:lol:
This is turning in to a good thread, at least from my standpoint. For the many of you that are fascinated by the technical aspects of DI resins.
OK, OK; I hear that chuckling back there!!! How are you dumb newbies going to learn without the grim details?
Virginiadiver,
I have an old lab Barnstead NanoPure system and they used Dow resins in the past. I'm not sure what they use now as getting cartridges for the units is somewhat difficult. However, it can crank out a liter per minute of 18.1-18.3 megaohm water per minute. Try getting that flow with any you may have at home.
This is turning in to a good thread, at least from my standpoint. For the many of you that are fascinated by the technical aspects of DI resins.
OK, OK; I hear that chuckling back there!!! How are you dumb newbies going to learn without the grim details?
Virginiadiver,
I have an old lab Barnstead NanoPure system and they used Dow resins in the past. I'm not sure what they use now as getting cartridges for the units is somewhat difficult. However, it can crank out a liter per minute of 18.1-18.3 megaohm water per minute. Try getting that flow with any you may have at home.
Rat you have told us that is what it is from your water supply companies assay. You even posted a link to it. I want to know what it is is at the tap water source at YOUR house and what it is post RO. There is no such thing as 120 ppm - 150 ppm post RO...period
AZDesertRat
In Memoriam
"Repeatedly I have asked you for your pH and Alk of your tap water but you do not seem to want to give it, which will resolve the issue on your tap water and DI resin depletion in relation to CO2."
I see the word TAP WATER above don't you? Quit being a &$*@. You asked for tap water I gave you tap water.
I see the word TAP WATER above don't you? Quit being a &$*@. You asked for tap water I gave you tap water.
And Newbies; we will soon have a cage match between Boom and Rat.
:eek1:
Be nice guys my newbies are easy to frighten.
:eek1:
Be nice guys my newbies are easy to frighten.
E-A-G-L-E-S
New member
I'm glad I saw this thread. I too have searched for a di resin that lasts longer. I only got 120g out of a brand new resin and I replaced the dow ro membrane at same time as the di replacement! Something is exhausting it at an alarming rate.
I'm going to test the Alk. and PH(gotta go buy a test) of my tap today.
I'm going to test the Alk. and PH(gotta go buy a test) of my tap today.
I should add that water with considerable levels of chloramines also exhaust the DI resin faster as the ammonia is not removed by carbon and passes through the RO membrane but why stir the pot.
virginiadiver69
New member
Stir away!
If someone can't handle the heat, they should stay out of the kitchen.
If someone can't handle the heat, they should stay out of the kitchen.
Thefilterguys
.Registered Member
Ammonia has an ion charge and as such registers as a TDS value. The rejection rate by a TFC membrane is 80-90 before DI for ammonia.
Jim
Jim
<a href=showthread.php?s=&postid=10159568#post10159568 target=_blank>Originally posted</a> by WaterKeeper
I should add that water with considerable levels of chloramines also exhaust the DI resin faster as the ammonia is not removed by carbon and passes through the RO membrane but why stir the pot.
RAT
You should know by now with all these post I have made that tap water and RO water are not the same. You should know by now with all these posts I have made that to determine the DI capacity it is the pH and Alk of the RO water. I wanted and have asked for both for comparison to see what variants there may be between the two in chemical nature.
Try re-reading this...........again........my last post to you
I want to know what it is is at the tap water source at YOUR house and what it is post RO. There is no such thing as 120 ppm - 150 ppm post RO...period
and this here is me guessing what might be going on.
On the other note a pH of 8 - 8.2 has about 2.5 ppm CO2. Pretty darn low for FW. If the effluent TDS was that 5 ppm, then 5 + 2.5 = 7.5 and 2.5 / 7.5 = 33 % of the DI will go to CO2.
and RO's remove much of the Alk. But we do't really know what your Alk is with out measuring it.
Is the murky water clear now. Try not to leave out questions I have asked, I know what they are.
This needs to be posted again only here on this thread.
Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm
You should know by now with all these post I have made that tap water and RO water are not the same. You should know by now with all these posts I have made that to determine the DI capacity it is the pH and Alk of the RO water. I wanted and have asked for both for comparison to see what variants there may be between the two in chemical nature.
Try re-reading this...........again........my last post to you
I want to know what it is is at the tap water source at YOUR house and what it is post RO. There is no such thing as 120 ppm - 150 ppm post RO...period
and this here is me guessing what might be going on.
On the other note a pH of 8 - 8.2 has about 2.5 ppm CO2. Pretty darn low for FW. If the effluent TDS was that 5 ppm, then 5 + 2.5 = 7.5 and 2.5 / 7.5 = 33 % of the DI will go to CO2.
and RO's remove much of the Alk. But we do't really know what your Alk is with out measuring it.
Is the murky water clear now. Try not to leave out questions I have asked, I know what they are.
This needs to be posted again only here on this thread.
Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm
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