New or Used RODI system? Which would u buy

[Javamahn]

I have a spectra pure 90 GPD that I purchased used two years ago I have replaced all the cartridges over that time of course but it's been a solid unit and still uses the same membrane. I would ask for proof of purchase for the cartridges and pictures of current tds

 

[Captain Quint]

Just my on RODI units. There are so many good units and many of us have a favorite brand which for the most part have the same final result of good stripped water. I'm not trying to promote one brand over another but would like to show an average cost of upkeep.

Several of us do change all blocks etcetera before selling and they are fine. Some sell them really low requiring replacement of most or all components.

The past ~20 years I've used the same brand and keep them in shape. I've had 3 during this time frame. Before selling I, in fact, replaced new blocks, membranes, and the DI resign so the buyer would have no issues.

I've had my current one for around 11 years replacing on a schedule as needed as far as membranes, blocks, and resign without issues.

I order blocks, and the DI resign for a year which I will show. I will also show the average cost of replacing the membrane which is the most expensive part. I've never used a built-in TDS meter. The handheld is cheap and works well for me.

Good luck in your consideration.

So I present an average yearly cost and an average 1-year average to keep an efficient RODI unit running properly.

The pic with the lower amount is a rough yearly average and the other which is more $ pic is roughly a 2-year average.

*sorry about 2 pics of the lower cost.

 

[Super Fly]

we need to back way up here. first you said you wanted low waste water? the “high efficiency” units work best with water that isn’t very hard. what is your tap tds?

also, all of the units mentioned thus far are not “high efficiency” low waste units.

https://spectrapure.com/RO-RODI/ROD...-1-1-Ultra-Low-Waste-Water-Ratio-RO-DI-System

around 170 TDS.
Thanks for the recommendation but sorry can't afford to spend $600 for a RODI unit especially when my current rodi has 5-1 waste-to-clean-water ratio and the BRS unit I ordered has 1.5-1 ratio. Meanwhile the Spectrapure model has 1-1 ratio, for a difference of only 0.50 ratio vs BRS unit, which is $400 less.

 

[cromag27]

around 170 TDS.
Thanks for the recommendation but sorry can't afford to spend $600 for a RODI unit especially when my current rodi has 5-1 waste-to-clean-water ratio and the BRS unit I ordered has 1.5-1 ratio. Meanwhile the Spectrapure model has 1-1 ratio, for a difference of only 0.50 ratio vs BRS unit, which is $400 less.

yeah, way more differences than just that. hope it works out for you though.

 

[Super Fly]

Several of us do change all blocks etcetera before selling and they are fine. Some sell them really low requiring replacement of most or all components.

The past ~20 years I've used the same brand and keep them in shape. I've had 3 during this time frame. Before selling I, in fact, replaced new blocks, membranes, and the DI resign so the buyer would have no issues..

We need more good honest people like urself.

 

[theMeat]

Sorry if I missed something, didn’t read the entire thread
If you already have an RODI just buy a BRS, or other, upgrade kit
Save water while producing more

https://www.bulkreefsupply.com/water-saver-upgrade-kit-bulk-reef-supply.html

FWIW, IMO, ime, you need good water pressure for anything over 75gpd. So if not, get a booster pump

 

[Super Fly]

Sorry if I missed something, didn’t read the entire thread
If you already have an RODI just buy a BRS, or other, upgrade kit
Save water while producing more

https://www.bulkreefsupply.com/water-saver-upgrade-kit-bulk-reef-supply.html

FWIW, IMO, ime, you need good water pressure for anything over 75gpd. So if not, get a booster pump

ordered BRS 150 gpd unit. My previous rodi was a small compact unit going thru too much cartridge n slow to produce water so was time to upgrade.
Yeah, house has good pressure and I already have a booster pump from current rodi that I will use on the new rodi

 

[theMeat]

ordered BRS 150 gpd unit. My previous rodi was a small compact unit going thru too much cartridge n slow to produce water so was time to upgrade.
Yeah, house has good pressure and I already have a booster pump from current rodi that I will use on the new rodi

Good to go...
Keep up on sediment and carbon filter maintenance and your membrane will last for years

 

[Buckeye Hydro]

Suggest you DO NOT add a second membrane plumbed in series. If all you want is a different waste water to purified water ratio, just change the $4 flow restrictor.
Russ

 

[vetteguy53081]

Either works. You replace the media and cartridges and good as new

 

[Captain Quint]

We need more good honest people like urself.

Thank you.

It's just that I'm known in the state I live and I will not sell anything whether it be a car, tanks or any equipment without it being correct.

My conscience is my guide. It really doesn't have anything to do with being honest but admit I do not care for one who does lie.

Just a feeling of satisfaction to me to know folks can depend on me as it should be.

 

[Javamahn]

incorrect. adding an additional membrane does not decrease waste.

It will decrease waste if the 2nd membrane is more efficient than the current 5:1

 

[Dr. Dendrostein]

Looking to upgrade my RODI to higher capacity with less waste-to-clean-water ratio. I buy mostly used equipment to save $ in this hobby however I'm struggling about not knowing how much life may be left on a used RODI system's membrane/cartridges. Would hate to potentially spend more $ having to replace cartridges/membrane sooner with a used unit vs just buying a brand new RODI and not having to deal with used cartridges/membrane.

Any thoughts?

I would buy new. Used unless you know how old it is, where it was used, like was there a water softener in that building. But knew can't go wrong

 

[Dr. Dendrostein]

it's too small (50gpd) that I was using with previous tank prior to upgrading tank. Besides, even with higher capacity gpd, this brand has too high waste-to-clean-water ratio (5-1)... would like to waste less water and save $ on water bill too.

Just remember an RO UNIT with no soft water thru it will only last 2-4years. Depends on water mineral content

 

[cromag27]

It will decrease waste if the 2nd membrane is more efficient than the current 5:1

what do you mean by “more efficient”?

 

[Javamahn]

what do you mean by “more efficient”?

if the membrane has the standard 4:1 ratio verses his current 5:1 ratio then processing 50% of the water through the 2nd membrane would reduce his waste. If a more limiting flow restrictor was placed on both membranes there would be reduce the waste and increased GPD with a maintenance downside of shorter membrane lifespan. I would like to see actual results of the BRS 1.5:1 and what the tested tap TDS was.

 

[cromag27]

if the membrane has the standard 4:1 ratio verses his current 5:1 ratio then processing 50% of the water through the 2nd membrane would reduce his waste. If a more limiting flow restrictor was placed on both membranes there would be reduce the waste and increased GPD with a maintenance downside of shorter membrane lifespan. I would like to see actual results of the BRS 1.5:1 and what the tested tap TDS was.

the membrane itself doesn’t dictate waste ratio. membranes are rated for product output (gpd) and rejection rate. there is no “standard” as there are other variables that effect waste ratio.

but you are correct in saying changing the flow restrictor can be beneficial. this is the key. any time you change membranes you want to verify your waste ratio and adjust the flow restrictor appropriately. so installing a “more efficient” membrane itself won’t do anything unless you also adjust the flow restrictor. but, you might as well adjust the flow restrictor without a new membrane, unless you need to produce more water.

 

[theMeat]

There’s no magic, or magic bullet. If you decrease the waste water with a smaller flow restrictor you also decrease membrane lifespan. Most recommend you shot for 4 to 1, unless saving water is more important than saving membrane.
If you use a second membrane run in series, then the waste water from the first membrane feeds the second, so your waste goes way down. But that comes at the cost of needing more psi, and a more complicated system.

 

[MartinWaite]

incorrect. adding an additional membrane does not decrwease waste.

No that is incorrect added a second membrane will decrease waste as the second membrane is fed the waste water of the first membrane. If you still don't believe it take a look at the BRS YouTube video on RO filters they recorded it actually shows how good the second membrane is.
As for 1.5-1 ratio it depends on quite a lot of things to achieve that ratio temp and pressure of water to be filtered and actual T.D.S. of incoming water and what you call acceptable RO water.

 

[cromag27]

No that is incorrect added a second membrane will decrease waste as the second membrane is fed the waste water of the first membrane. If you still don't believe it take a look at the BRS YouTube video on RO filters they recorded it actually shows how good the second membrane is.
As for 1.5-1 ratio it depends on quite a lot of things to achieve that ratio temp and pressure of water to be filtered and actual T.D.S. of incoming water and what you call acceptable RO water.

by your own admission it doesn’t decrease waste. it merely passes it to the second membrane. so that’s great, burn through membranes faster! again, a correctly sized capillary flow restrictor is really going to dictate waste ratio, within limits.