RO vs RODI

[wilson_the_volleybal]

Hi all

This may be a dumb question.

I live in a condo, so installing a full RODI system is a bit difficult (I rent). I have found a portable one, that may be a bit slow in generating water, but it would work fine if I do it in advance. However, it is only RO water as the output. Would that be fine?

Thank you!

 

[wvned]

You could just put an additional canister on the output with resin and you would have RODI.

 

[discotu]

RO only might be okay. What is the TDS of your source water? What type of tank do you keep? SPS, mixed, fish only etc. Are you okay with potentially dealing with more nuisance algae? As mentioned above you can always add a DI stage and is relatively inexpensive.

 

[wilson_the_volleybal]

Okay, that is good to know.

I don't have a TDS tester at the moment, but from Google, it is 3.25 (not sure if that is good or bad).

this is what I am looking at getting as I can store it easily, and set it up when I need to make RO water.

Amazon.ca

Although, looking at it, it may have a DI filter.

 

[wvned]

it does

 

[wilson_the_volleybal]

Ordered. thank you!

 

[griss]

Glad you found something that will work for you.

 

[Cruzersmith]

Don’t want to poach the OPs thread but I’m wanting to know what exactly the DI mixed bed resin is removing?

 

[griss]

Don’t want to poach the OPs thread but I’m wanting to know what exactly the DI mixed bed resin is removing?

It depends what's in your tap water. Mixed bed DI is a mixture of Anion and Cation resins. Cation removes positively charged cation molecules such as calcium, magnesium, iron and sodium. Anion removes negatively charged molecules such as chloride, sulfates, nitrates, carbonates and silicates.

Now, you might say, you don't want to remove calcium and magnesium but, IMO the benefit of removing the other molecules (and the ease of adding calcium and magnesium back to water) outweighs the removal.

My post RO membrane water runs about 6-10 TDS. My water then passes through Cation, then Anion, and finally a mixed bed. The resulting TDS of the water is zero. Upon mixing with salt mix (I just use good ole IO) the parameters for calcium, magnesium, etc. are spot on for a reef tank.

 

[Cruzersmith]

I assume being you’re experienced in this that you have done all you can pre ion resin. Without knowing your source water hardness and temperature and whether you have a booster pump I don’t know how good 6 to 10 ppm is or how much resin it takes to make it 0.

 

[Patrick Seastar]

I know this doesn’t have anything to do with your question but your thread reminded me of people that used to claim that distilled water shouldn’t be used because it can have copper in it … Ah, boy, funny people with funny theories. Like other users said, chemical filtration can remove that for you bio-load permitting.

 

[wvned]

It wasn't funny when distillation plants were built with copper piping.

 

[griss]

I assume being you’re experienced in this that you have done all you can pre ion resin. Without knowing your source water hardness and temperature and whether you have a booster pump I don’t know how good 6 to 10 ppm is or how much resin it takes to make it 0.

Fair enough. I don’t know my source water hardness, never tested it but my area has pretty hard water. Whole house water softeners are pretty common here.

Temp of source water depends on the time of year. Temps in the summer are pretty hot and in the winter can get pretty damn cold.

Yes, I do use a booster pump as my home water pressure is not the best.

 

[griss]

To add, the current resin I have in my canisters has be there for over a year and is still good. I’d rather be safe than sorry.

 

[griss]

It wasn't funny when distillation plants were built with copper piping.

I remember those days Ned.

 

[Cruzersmith]

Thanks. I mention it because my source water is 320ppm+ and its temperature ranges from 50 to 55 degrees F.
I’m wondering if I should use water from my softener and mix in some hot to bring the temperature up to cut down on the waste . My water utility report says I have a variety of issues all mostly in low amounts. The one concern is 5.1 to 5.9 ppm of nitrate. Not counting the Barium,Chromium, copper, fluoride , Lead, Nickel and Selenium . Even some radio active contaminants. None of this ever seemed to effect the fresh water fish I kept for decades.

 

[Patrick Seastar]

It wasn't funny when distillation plants were built with copper piping.

Yeah, I know but it’s funny that some aquarists still believe it is. Copper coils haven’t been used since many decades so I found it funny when people lectured others over the use of distilled water & get into heated arguments

 

[wvned]

Yeah, I know but it’s funny that some aquarists still believe it is. Copper coils haven’t been used since many decades so I found it funny when people lectured others over the use of distilled water & get into heated arguments

Wasn’t is past tense. I don’t get into heated arguments

 

[Patrick Seastar]

Wasn’t is past tense. I don’t get into heated arguments

Yup, that’s what I mean as well. Wasn’t talking about you but, ok I guess

 

[kharmaguru]

I love distillation.