Let’s talk water... distilled vs RODI

[ReefSarg]

Lately I’ve been looking into purchasing a distillery for my top off water, and even for water changes as opposed to continuing the never ending cycle of buying RO filters. Anyone out there can shed some light on why distilleries aren’t used in the hobby? Seems like perfect H2O would be most desired. Pic for attention

 

[Weasel1960]

I will be interested to see your answers as I have been wondering about the necessity of using RODI. The only thing I can say about distilling is that some low boiling point impurities will get through the system with the water. You would have to know if those exist in your source water or not.

 

[Karen00]

I think it has something to do with the copper pipes used in the distilling machines. I believe it's fine for FOWLR but not good for some corals. I don't think contaminants in the source water end up in the final water. I think those are left behind unless the contaminant has the same boiling point as water. Having said that I will be interested to see other responses as I just started looking into this as well. I think there was another thread on here about distilled which referenced something about the copper (I think). I'm trying to find the thread. I will post it if I can find it.

 

[ReefSarg]

I will be interested to see your answers as I have been wondering about the necessity of using RODI. The only thing I can say about distilling is that some low boiling point impurities will get through the system with the water. You would have to know if those exist in your source water or not.

thats interesting. Only thing as far as I’ve read is that distilleries that use metal piping such as copper could contaminate the water some with trace elements. Which is why plastics are used now.

 

[Karen00]

thats interesting. Only thing as far as I’ve read is that distilleries that use metal piping such as copper could contaminate the water some with trace elements. Which is why plastics are used now.

Yes but I think you have to make sure the piping is plastic. There were some comments in the other thread that mentioned copper was still being used. I think that was one of the concerns.

 

[Opus]

I think it is a cost issue, but that would be different for every person. Doing "rough" math for my ro setup, I change out my prefilters once a year and the di is about once a year. Total cost to change them all out is about $55. Add to that around $10 a year for the ro membrane allocation since it cost around $50 and it will last around 5 years. That makes my ro maintenance costs around $65 per year. I figure I use around 800 gal of water a year so that means I use a little over 3000 gal of water assuming I'm getting a 1 to 3 rejection thru the ro unit. I'm charged around $6 per 1000/gal so that is $24 in water charges each year. So that brings my ro yearly costs to $89.

Looking at the distillery, the website I found said it cost around $.36 to make a gallon of water in electricity cost and over 3 hours to do it. That would make my 800 gal of water usage cost $288 in electricity cost each year. Plus the time issue of over 3 hours for a gallon of water vs around 15 minutes with the ro unit.

 

[Zionas]

I’ve thought about distilled water too but when all I have is Chinese distilled water..... Guess RODI is still the safer option.

 

[Karen00]

The search function isn't working for me at the moment. I will try to find the other thread. As mentioned the copper issue only impacted certain corals if I remember correctly so it wasn't an issue for every saltwater tank and if you got one that didn't use any copper you were fine. I think the only other comment was it took longer to get a batch of distilled water made Frome a home unit vs a RODI system so it might not make sense if you need large volumes but I might not be remembering that correctly. It is something to look at though when looking at units.

 

[Weasel1960]

The link below talks about things like pesticides etc. that may be in the water. These have a lower boiling point than the water itself so steam off and go up the tube first. Just to be clear I am not suggesting all water has this problem but you should know what is in your water to start with.

Understanding Distilled vs. Purified Water

Curious about the differences between distilled and purified water? Learn why we recommend purified water. Start your delivery today.

www.drinkmorewater.com

 

[Weasel1960]

I think it is a cost issue, but that would be different for every person. Doing "rough" math for my ro setup, I change out my prefilters once a year and the di is about once a year. Total cost to change them all out is about $55. Add to that around $10 a year for the ro membrane allocation since it cost around $50 and it will last around 5 years. That makes my ro maintenance costs around $65 per year. I figure I use around 800 gal of water a year so that means I use a little over 3000 gal of water assuming I'm getting a 1 to 3 rejection thru the ro unit. I'm charged around $6 per 1000/gal so that is $24 in water charges each year. So that brings my ro yearly costs to $89.

Looking at the distillery, the website I found said it cost around $.36 to make a gallon of water in electricity cost and over 3 hours to do it. That would make my 800 gal of water usage cost $288 in electricity cost each year. Plus the time issue of over 3 hours for a gallon of water vs around 15 minutes with the ro unit.

My last aquarium before life got in the way was 30 years ago. RODI wasn’t a thing yet and I had hard municipal water in an apartment. I rented a distiller from Culligan an remember it took a whole day to get 5 gallons. Fortunately I only had 2-25 gal tanks but I kept 15 gal ready all the time because it took so long.

 

[Opus]

The link below talks about things like pesticides etc. that may be in the water. These have a lower boiling point than the water itself so steam off and go up the tube first. Just to be clear I am not suggesting all water has this problem but you should know what is in your water to start with.

Understanding Distilled vs. Purified Water

Curious about the differences between distilled and purified water? Learn why we recommend purified water. Start your delivery today.

www.drinkmorewater.com

The stuff I've read said a lot of them have a carbon filter in them now that get rid of all the stuff that like that. Of course that adds another maintenance cost to the unit.

 

[chipmunkofdoom2]

Chances are you would get much better return on investment if you test your RO filters and only replace them when necessary. My last RO membrane lasted for 10+ years. My current prefilters are 2+ years old. My water is relatively low TDS (180 - 190 ppm) and contains chlorine instead of chloramine, so that plays a part. Still, I only know my filters are still good because I actually test them instead of just replacing them on a schedule.

 

[blasterman]

Distilled water passes on chemicals that have a lower vapor point than where water boils. Thats true, but if you have that much of a problem with your source water it's likely not safe to drink in the first place.

R/O just scales better for most aquarium use.

Where I have a bone to pick is with commercial water. There's only one way to make distilled water while R/O water from the reef store/grocery store varies depending on how well they keep it maintained. The worst commercial water I've bought has been R/O. Distilled has never let me down.

 

[ReefSarg]

The link below talks about things like pesticides etc. that may be in the water. These have a lower boiling point than the water itself so steam off and go up the tube first. Just to be clear I am not suggesting all water has this problem but you should know what is in your water to start with.

Understanding Distilled vs. Purified Water

Curious about the differences between distilled and purified water? Learn why we recommend purified water. Start your delivery today.

www.drinkmorewater.com

Yeah that’s good info, so I’m theory if my water source was reasonably ok I could use a distillery as my primary source for tank water

 

[airmotive]

Former Navy nuclear operator here. We made lots of very pure water on my aircraft carrier. Distillation was only the first step of water purification for us. We could make 40,000 gallons of distilled water a day. That went into steam generators, washing aircraft, catapults and if any was left over, for drinking fountains and crew showers.
It wasn't pure, but it was pure enough to drink and clean aircraft. You wouldn't want to have really pure water for drinking; it would make you sick.
Next we had charging water day tanks. These were tanks of distilled water that we would heat to just below boiling for 72 hours. This would drive out any dissolved gasses or other volatile impurities. This would give you the equivalent of RO water. Finally, before that water was injected into the reactor plant, it would go through a deionizor vessel that was about the size of a minivan. That's RODI water...just on a larger scale.

Distilling water is very energy intensive. The latent heat of vaporization for water is huge. We would use a vacuum chamber to distill water because it took so much thermal energy to do it at atmospheric pressure (and we had the power of two nuclear reactors at our disposal).

 

[Randy Holmes-Farley Verified Community Expert]

Some folks do distill their own water for reefs, but unless your energy is cheap, it can be a very costly enterprise to raise it all to steam.

 

[Weasel1960]

Former Navy nuclear operator here. We made lots of very pure water on my aircraft carrier. Distillation was only the first step of water purification for us. We could make 40,000 gallons of distilled water a day. That went into steam generators, washing aircraft, catapults and if any was left over, for drinking fountains and crew showers.
It wasn't pure, but it was pure enough to drink and clean aircraft. You wouldn't want to have really pure water for drinking; it would make you sick.
Next we had charging water day tanks. These were tanks of distilled water that we would heat to just below boiling for 72 hours. This would drive out any dissolved gasses or other volatile impurities. This would give you the equivalent of RO water. Finally, before that water was injected into the reactor plant, it would go through a deionizor vessel that was about the size of a minivan. That's RODI water...just on a larger scale.

Distilling water is very energy intensive. The latent heat of vaporization for water is huge. We would use a vacuum chamber to distill water because it took so much thermal energy to do it at atmospheric pressure (and we had the power of two nuclear reactors at our disposal).

From one vet to another...thanks for your service.