RODI system questions

Freenow54

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Trying to reduce waste water is not a win win. It has drawbacks of various sorts.

The entire RO/DI process is detailed here:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com
I am not keeping this going to defend any manufacturer. Everyone is quite capable of making their own decisions. Trusting they research things. I merely posted because someone wanted ideas. Randy for instance is a chemist I gather and has way more knowledge and resources than I do to talk about that subject I certainly wont ever challenge his or other professional or established reefers unless I do have experience and knowledge
 

Freenow54

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If that second use is cold water before heating, I'd go that way. If it is heated water, some other option will be better.
Not heated water. That is one drawback. It takes about 24 hours to fill a 40 gallon vessel. When its running you have to turn the hot lever up more. I experimented and others do no complain about it so great
 

Randy Holmes-Farley

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Not heated water. That is one drawback. It takes about 24 hours to fill a 40 gallon vessel. When its running you have to turn the hot lever up more. I experimented and others do no complain about it so great

I am not really understanding how this relates to my post, but since I do not have a tankless heater, perhaps I do not understand where the take off of water for the RO/DI is in relation to the heating element..
 
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SaltWaterTank_Noob

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@SaltWaterTank_Noob, it seems that this side discussion is confusing you to what should be simple.

Your questions are that of anyone coming into the hobby and trying to navigate the subject of RODI.

The 2 options that you mentioned in your 1st post are common. And based on your question it seems you're budget savvy. I will offer my thoughts in hopes to steer you into making an informed decision.

The RODI buddy is definitely a budget friendly option, however when it comes time to service the filters you're subject to their proprietary filters and their pricing. The BRS version uses traditional size filters that can be purchased from unlimited suppliers. The extra upfront cost needs to be weighed with longterm use and servicing.

As for chloramine or chlorine, that is handled on the prefilter side (sediment > carbon block). Choosing the right carbon block with the right micron filter will address chloramine concerns. I assume that my water supply has chloramine and purchase the correct carbon blocks.

As the thread progressed you had other questions about rejection rate, and that's where RO units separate. There are companies out there who's business is water filtration. They focus more on efficiency and differing mixtures of DI for reef tanks. You mentioned that Spectrapure is double the cost of the leading brand and I believe that's because they make a superior product.

That doesn't mean you should rush to buy their units, it's more of understanding the differences. Their membranes/flow restrictor can fit into most RO housings to provide a better rejections rate. And the same goes for their prefilters and DI.

However, if you go with the rodi buddy, none of those can be an option. At the very least you should consider purchasing a unit with universal canister sizes.

I hope the side conversation of zero waste isn't muddying the waters for you... sadly I fear that it's has.
hahaha thank you! I was thinking that I might go with the BRS 75GPD 4 stage that has the TDS tester and pressure gauge. It seems like from what you are saying is the few gallons a week savings, even justifiable and you might be right.
 
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SaltWaterTank_Noob

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If that second use is cold water before heating, I'd go that way. If it is heated water, some other option will be better.
This is my water heater setup, I am unsure as to what you mean if the cold water before heating.
20250210_131946.jpg
 

Freenow54

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I am not keeping this going to defend any manufacturer. Everyone is quite capable of making their own decisions. Trusting they research things. I merely posted because someone wanted ideas. Randy for instance is a chemist I gather and has way more knowledge and resources than I do to talk about that subject I certainly wont ever challenge his or other professional or established reefers unless I do have experience and knowledge
Interesting article I was wondering if you can recharge that DI resin. I used to work for culligan when I was very young and recharged the soft water resin. But of course entirely different process just salt . Obviously did not read it all the way through but will. Still waiting for an answer regarding the importance of trace elements. Is there an article on that?
 

Sisterlimonpot

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I don't make these things up.
Your explanation of how a backflow preventor works is correct, however your application of it in the system doesn't offer any protection in this scenario. The primary principle of the backflow works off of pressure differential. To enlarge the main purpose is if city pressure dropped, water in the house ie upper tank toilet water won't siphon back into the water supply. This does very little to prevent a presuized system on both sides to stop backflow. When you're forcing water back into an already pressurized system that volume and extra pressure has to go somewhere, hence my theory of out the pressure relief of the hot water heater or back into the city supply.

...to me, it just doesn't add up.


Also new homes here have to have an undefeatable temperature limiter otherwise known as a mixing valve installed off water heater to protect the innocent
I don't understand what merit that has with this conversation.
 

Sisterlimonpot

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hahaha thank you! I was thinking that I might go with the BRS 75GPD 4 stage that has the TDS tester and pressure gauge. It seems like from what you are saying is the few gallons a week savings, even justifiable and you might be right.
Providing your options, that's the decision I would've made as well. If in the future you decide that waste water is a concern for you, you're left with options to upgrade.
 
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SaltWaterTank_Noob

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Providing your options, that's the decision I would've made as well. If in the future you decide that waste watee is a concern for you, you're left with options to upgrade.
Lol how would I even know that waste water is a concern or should be a concern?
 

Sisterlimonpot

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Lol how would I even know that waste water is a concern or should be a concern?
For most it isn't, every few months you'll see a thread pop up about how people utilize thier waste water. The topic of zero waste would be a perfect conversation in one of those threads.
 

Randy Holmes-Farley

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This is my water heater setup, I am unsure as to what you mean if the cold water before heating.
20250210_131946.jpg

Where do you propose getting water to run into the RO/DI if that is where you set it up?
 

Randy Holmes-Farley

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Interesting article I was wondering if you can recharge that DI resin. I used to work for culligan when I was very young and recharged the soft water resin. But of course entirely different process just salt . Obviously did not read it all the way through but will. Still waiting for an answer regarding the importance of trace elements. Is there an article on that?

Are you asking me? Some folks recharge DI resins, but I never found it worth the time required.

I discuss trace elements in these articles:


 

Freenow54

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I ham a little miffed as to the fact that unless someone responds to my post then I cannot see any other statements. That and adding photos is a pain. There was a post about costs. My email wont let me send some photos as file too large was from Amazon. only have one of the cartridges replacement bear in mind all Canadian dollars so you would pay way less. The DI cartridge which comes filled is made by aquatic life and is $35, I also bought replacement resin again Aquatic life 5 liters 8.14 pounds $ 129. I have changed the resin about 6x and still have 2/3 left. You cannot let it dry out or expose to the sun. I made a storage
20250210_152608 (1).jpg
container using a 3 inch abs pipe with a screwed end on it. Works great
 

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