Used RO/DI?

[cartery]

Hello! I'm very new to reefing and trying to learn about RO/DI. I found a used 7 stage for sale for $100. The seller is recommending that I drop about $80 on filter replacements if I purchase from them. The system is around 7 years old and has been expanded over time. This seems like a good deal to me, but I really have no idea. What do people think? Any other questions I should definitely ask? Anything I should check if I see it in person? Thank you!

 

[Solo McReefer]

If you do get it, it is a good deal if a name brand

Recommend
Replace all the filter materials and the RO membrane

 

[cartery]

If you do get it, it is a good deal if a name brand

Recommend
Replace all the filter materials and the RO membrane

Yup, name brand. Thanks for the input!

 

[Dburr1014]

Hello! I'm very new to reefing and trying to learn about RO/DI. I found a used 7 stage for sale for $100. The seller is recommending that I drop about $80 on filter replacements if I purchase from them. The system is around 7 years old and has been expanded over time. This seems like a good deal to me, but I really have no idea. What do people think? Any other questions I should definitely ask? Anything I should check if I see it in person? Thank you!

It also depends on your water in your area and what your needs are.

For instance, my incoming water is 40ish TDS. I have a whole house filter with a 4' carbon canister. So my RODI consists of the membrane and anion/cation/mixed bed. That's all. I haven't changed my membrane in probably 3 years. Still get 2 TDS from that and zero finished product.

 

[Dbichler]

I don’t know what filter replacements they used but it will be way more than $80. Di resin is going to cost you almost that much if not more.

 

[Reefer AJ]

I would also think about futuristic use. With you saying it will be 80 bucks to replace all the filters, it sounds like it may be a brand that has specific filter replacements with pre-fitted o ring connections. These can be great for ease of use (twisting old one off and twisting the new one back on for replacement and your done), however, you will generally pay more overall for these types of units cartridge replacements. The reason for this is you are buying an entire cartridge prefilled every time rather then buying a bulk supply of that you can fill your reusables with instead (more upfront cost but less long run cost). Just something to think about.

 

[cartery]

The seller says that the system is a mix of spectra and BRS, comparable to https://www.bulkreefsupply.com/7-stage-pro-75-gpd-ro-di-system-bulk-reef-supply-bundle.html. They say they recently replaced the RO filter and recommend getting this refill for the rest https://www.bulkreefsupply.com/7-stage-pro-ro-di-replacement-filter-kit-bulk-reef-supply-bundle.html. So actually $90, not $80.

 

[cartery]

It also depends on your water in your area and what your needs are.

For instance, my incoming water is 40ish TDS. I have a whole house filter with a 4' carbon canister. So my RODI consists of the membrane and anion/cation/mixed bed. That's all. I haven't changed my membrane in probably 3 years. Still get 2 TDS from that and zero finished product.

My TDS is pretty dang high. I don't remember the specifics, but I checked the tap water and it was up there

 

[cartery]

I would also think about futuristic use. With you saying it will be 80 bucks to replace all the filters, it sounds like it may be a brand that has specific filter replacements with pre-fitted o ring connections. These can be great for ease of use (twisting old one off and twisting the new one back on for replacement and your done), however, you will generally pay more overall for these types of units cartridge replacements. The reason for this is you are buying an entire cartridge prefilled every time rather then buying a bulk supply of that you can fill your reusables with instead (more upfront cost but less long run cost). Just something to think about.

Posted the recommended replacement below. Are those the predicted ones you refer to?

 

[Reefer AJ]

My TDS is pretty dang high. I don't remember the specifics, but I checked the tap water and it was up there

Looks like your in Tucson, lived there for almost 20 years before moving to FL. Tucson water is known for being quite hard. Hard water contains high levels of calcium and magnesium, which can lead to mineral buildup on fixtures, appliances, and in pipes, which in turns leads to corrosion amongst other things. This is harder on the RODI unit so you may just expect to have some more replacements a little more frequently then what the manufacturer may state since they are probably going off averages but it will be unknown until you test it for yourself. This is assuming you are on city water and not well water. On that note it may be wise to install pressure meters between your units to track there wear if it doesn't already have that.

Also another topic of interest you may want to look into is if the city is still using chlorine to remove water contaminates or if they have switched to chloramines (as a lot are). If they have switched to chloramine that is something you need to know to tailor your filter as chloramines are more challenging to remove than chlorine. Carbon filters are less effective at removing chloramines because they require a longer contact time and a special type of carbon called catalytic carbon to break down the chloramines effectively. RO/DI systems that use standard carbon filters may not fully remove chloramines and Chloramines are toxic to fish and can cause stress, illness, or even death if they are present in high concentrations. They can damage the gills, disrupt the fish’s respiratory system, and interfere with the fish's ability to absorb oxygen.

 

[Reefer AJ]

Posted the recommended replacement below. Are those the predicted ones you refer to?

Yeah that looks good, looks like you can refill your units individually. After a while as you learn which parts may go out sooner then others you can buy bulk of individual items as well.

 

[cartery]

Looks like your in Tucson, lived there for almost 20 years before moving to FL. Tucson water is known for being quite hard. Hard water contains high levels of calcium and magnesium, which can lead to mineral buildup on fixtures, appliances, and in pipes, which in turns leads to corrosion amongst other things. This is harder on the RODI unit so you may just expect to have some more replacements a little more frequently then what the manufacturer may state since they are probably going off averages but it will be unknown until you test it for yourself. This is assuming you are on city water and not well water. On that note it may be wise to install pressure meters between your units to track there wear if it doesn't already have that.

Also another topic of interest you may want to look into is if the city is still using chlorine to remove water contaminates or if they have switched to chloramines (as a lot are). If they have switched to chloramine that is something you need to know to tailor your filter as chloramines are more challenging to remove than chlorine. Carbon filters are less effective at removing chloramines because they require a longer contact time and a special type of carbon called catalytic carbon to break down the chloramines effectively. RO/DI systems that use standard carbon filters may not fully remove chloramines and Chloramines are toxic to fish and can cause stress, illness, or even death if they are present in high concentrations. They can damage the gills, disrupt the fish’s respiratory system, and interfere with the fish's ability to absorb oxygen.

Yup, Tucson. Looks like we're still on chlorine, but good call https://www.tucsonaz.gov/Departments/Water/Water-Quality/Aesthetics/Taste.

And yeah, the water here is intense. We need to use distilled in various appliances just to keep them alive.

Thanks for the info!

 

[Reefer AJ]

Yup, Tucson. Looks like we're still on chlorine, but good call https://www.tucsonaz.gov/Departments/Water/Water-Quality/Aesthetics/Taste.

And yeah, the water here is intense. We need to use distilled in various appliances just to keep them alive.

Thanks for the info!

Nice that will make things easier and cheaper on you. Glad it was an easy search for you, my county wasn't listed on there website and I ended up going down a goose chase of different calls to find my answer lol.

I hear you on that, its needed especially for your drinking water as well. Good luck to you, enjoy those mountains, I miss them!

 

[cartery]

Nice that will make things easier and cheaper on you. Glad it was an easy search for you, my county wasn't listed on there website and I ended up going down a goose chase of different calls to find my answer lol.

I hear you on that, its needed especially for your drinking water as well. Good luck to you, enjoy those mountains, I miss them!

Thanks! I'll wave to the Catalinas for you