Rodi questions (1 Viewer)

[Varig]

That's an interesting comment about replacing carbon/sediment sooner than DI resin. My original mix bed resin (with brand new cartridges obvi) only lasted about 100 gallons. Are you suggesting I should have considered changing my carbon/sediment in less than 100 gallons? I'm a newbie, so feel free to tell me that's correct. Note, I do realize that with the RO rejection that to make 100 gallons of RO/DI the sediment/carbon blocks saw more than 100 gallons. But I thought they were good for much longer?

Regardless, I bought a double DI cartridge after going through 2-3 single mixed beds in ~100 gallons. It came filled with mixed bed, but as soon as that is depleted I have the anion/cation to try. Fingers crossed that will make a difference. But do let me know on those first cartridges if there is an expected life in gallons. I have the setup that is sediment, carbon, carbon if that makes any difference.

Cheers!

 

[reef junkie]

That's an interesting comment about replacing carbon/sediment sooner than DI resin. My original mix bed resin (with brand new cartridges obvi) only lasted about 100 gallons. Are you suggesting I should have considered changing my carbon/sediment in less than 100 gallons? I'm a newbie, so feel free to tell me that's correct. Note, I do realize that with the RO rejection that to make 100 gallons of RO/DI the sediment/carbon blocks saw more than 100 gallons. But I thought they were good for much longer?

Regardless, I bought a double DI cartridge after going through 2-3 single mixed beds in ~100 gallons. It came filled with mixed bed, but as soon as that is depleted I have the anion/cation to try. Fingers crossed that will make a difference. But do let me know on those first cartridges if there is an expected life in gallons. I have the setup that is sediment, carbon, carbon if that makes any difference.

Cheers!

Everything Im reading says if you see a drop in pressure that the micron is probably full and need of replacing, and the carbon should be replaced after 6-12 months, then membrane when you see a rise in TDS before the Di. Im not seeing anything that specifies gallons. Only time and or readings. In the case of my DI it sounds like maybe its the access salt from my softner that is maybe causing this to deplete quicker.

I also will be switching to anion/cation. Did not know that this was even a thing. Makes me think what other little secrets am I missing out on

 

[spsick]

That's an interesting comment about replacing carbon/sediment sooner than DI resin. My original mix bed resin (with brand new cartridges obvi) only lasted about 100 gallons. Are you suggesting I should have considered changing my carbon/sediment in less than 100 gallons? I'm a newbie, so feel free to tell me that's correct. Note, I do realize that with the RO rejection that to make 100 gallons of RO/DI the sediment/carbon blocks saw more than 100 gallons. But I thought they were good for much longer?

Regardless, I bought a double DI cartridge after going through 2-3 single mixed beds in ~100 gallons. It came filled with mixed bed, but as soon as that is depleted I have the anion/cation to try. Fingers crossed that will make a difference. But do let me know on those first cartridges if there is an expected life in gallons. I have the setup that is sediment, carbon, carbon if that makes any difference.

Cheers!

You’d be surprised how fast chlorine/chloramine blow through carbon blocks. Not only does chlorine kill membranes and DI- it gets converted to ammonia- not good! I got the fancy Hach kit and did a bunch of testing a few years ago to figure it out- I was getting chlorine blow through at 6 weeks on the first carbon block. I now replace my #1 carbon block every 2 month and #2 carbon block every 6 months. If you red the specs on the BRS Universal carbon block (the best in my testing) you’ll note that the rating (3500g) is for 85% reduction- we need 100%!

To go through a DI in 100g of product water is crazy. That tells something isn’t right on your unit (or carbon and membrane are shot).

If you go the cation/anion route you do need 3- cation, anion, and the mixed bed to even ions out.

 

[Varig]

Interesting. Yea I haven’t done the CO2 test (people say that will also blow through DI resin). I guess that’s what I’ve been assuming was the issue. As mentioned, it burnt DI that fast from having brand new everything. The tds meter, if you can trust it, reads 2-3 coming out of the RO membrane, so I think that is working. I looked up our city water supply and I don’t see any mention of chloamine, just chlorine.

I was going to switch over to the 1micron carbon block to see if that changed anything. And the 3 stage DI as you mentioned, cation/anion followed by mixed bed. If it’s still burning resin then I guess I’d need to check the co2 hypothesis. I really hope it’s not that, it sounds like a huge PITA to make RO water, let it sit open for a few days with a pump, then pump it through the DI stages. Barf.

I also just sent off an ATI ICP test. I’m curious if they find anything in my RO water. Hopefully not obviously, but that could be telling as to why I’m burning resin if they do.

 

[spsick]

Interesting. Yea I haven’t done the CO2 test (people say that will also blow through DI resin). I guess that’s what I’ve been assuming was the issue. As mentioned, it burnt DI that fast from having brand new everything. The tds meter, if you can trust it, reads 2-3 coming out of the RO membrane, so I think that is working. I looked up our city water supply and I don’t see any mention of chloamine, just chlorine.

I was going to switch over to the 1micron carbon block to see if that changed anything. And the 3 stage DI as you mentioned, cation/anion followed by mixed bed. If it’s still burning resin then I guess I’d need to check the co2 hypothesis. I really hope it’s not that, it sounds like a huge PITA to make RO water, let it sit open for a few days with a pump, then pump it through the DI stages. Barf.

I also just sent off an ATI ICP test. I’m curious if they find anything in my RO water. Hopefully not obviously, but that could be telling as to why I’m burning resin if they do.

That’s a good point about the co2 that I forget as I have not encountered personally. I know Adam at Battlecorals has preached about it and even went so far as to make a holding tank to aerate water before running in through DI as you mention.

 

[Varig]

Yea fair enough. I have no idea why one area would be higher than others. Or maybe there is a way to test dissolved CO2 so I wouldn't have to mess around with the storage option to test things? Regardless, at this point I don't need that much water for my ~55 gallon total system volume (DT and coral QT). With 10% water changes weekly, I go through ~300 gallons of SW per year and another ~150 gallons of RODI for top off. So I guess put like that it's a decent bit of water, but nothing compared to some of you guys. So there is also a part of me that says "Well if I blow through a little extra DI resin, it might be worth it versus messing around with 2 stage CO2 removal."