rodi wastewater

neotekz

Premium Member
is there a system out there that can reduce the amount of wastewater from a rodi system? my aquasafe uses about 2.5g per one gallon of rodi. is there any system that is more efficient? i know that a rodi system has to reject some water to work properly but is there a system out there that is more efficient? also i'm a little confused about rejection rates...what;s the difference between the higher 98% and 90%? does that mean that the 98% rejection rate RO membrane produces more wastewater per gallon?

also what is a good rodi? i was looking at the maxpure from spectrapure.com, anyone use this system?
 
The rejection rate specifies the approximate percentage of TDS the membrane should remove, basically. It does not imply anything about the wastewater rate. There are systems with lower waste rates, but yours is doing fairly well.

The MaxCap resin seems to get good reviews, and SpectraPure does, too.
 
The MaxCap RO/DI is the undisputed best unit on the market today bar none. It uses features no one else offers like 100% hand tested and guaranteed 98+ % rejection rate RO membranes and the exclusive SilicaBuster and MaxCap DI cartridges. Mine is actually averaging 99.25% rejection rate with the RO only. 98% is about 10 times better than 90% when it comes to final water quality and DI resin life.
Rejection rate has nothing to do with the waste ratio. It is the amount of salts, solutes or contaminants removed from the tap water. Waste ratio is the amount of water you use to flush the contaminants off the membrane while it is in operation, this is usually 4:1 or 4 waste to 1 good.
A very important piece of information to remember is for every 2% you increase the RO membranes efficiency you DOUBLE the life of the DI resin. So if you go from a 90% rejection membrane to a 98% rejection rate membrane you have probably quadrupled the life of the DI system for much better quality and longer life. A good system pays for itself very quickly if you make much water at all.
Spectrapure has a system under development that I have had the opportunity to see a few times that should turn the RO/DI world on its ear. It will be microprocessor controlled and have a waste ratio of 1:1 or 1 good to 1 waste and possibly even better than that without sacrifycing membrane life or water quality. It will still deliver 98+ % effeiciency an last for years and years due to its unique design. I am told it will be on the market as soon as the bench testing is completed. They will not release it until they are 100% sure of its quality. I can't wait myself.
 
microprocessed controlled...do you think i should wait? is it going to cost an arm?
i was looking at the Maxpure not the maxcap, whats the difference besides the extra di stage? what's the wastewater rate on you maxcap AZDesertRat?
 
For what it will offer I think it would be worth the wait myself if I didn't already own a 150 GPD MaxCap RO/DI system. I don't know the price or availability you will have to contact Spectrapure.
My waste ratio is 4:1. My tap water TDS is about 800 so I like to keep my membrane well flushed. The new system the yare developing will be very unique with auto flushing built in using DI water instead of tap water for a much better flush and probably longer life. Who knows I may have to upgrade when it comes out! Knowing me, I probably will, I'm a water quality junkie!
 
I know they make a booster pump which use the waste water and change the ratio to 1:1.

Dunno how much they cost, it use no electricity, hydraulic force.
 
i was just looking at the spretrapure site and saw this, http://www.spectrapure.com/St_permeate_pump.htm
i think that's what you're talking about, i'm not sure how it works though. it claims to reduce wastewater up to 80% but you need one of those external pressure tanks.

AZDesertRat-what's the difference between the Maxcap system and the MaxPure system? as far as i can see the maxcap has the second DI and TDS meter, is there anything else?
 
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The Max Cap gets you seperate DI cartridges with the first one being the MaxCap or roughing cartridge and the second the Silica Buster cartridge for a final polishing. It also uses a 20,000 gallon capacity 0.5 micron carbon block. And it gets you a second dual inline TDS meter for a total of 4 monitoring points so you can evaluate the entire system component by component.
The DI life out of the MaxCap is far superior to even the MaxPure system. With normal mixed bed DI reisin like in the MaxPure I get 150 gallons per 24 oz cartridge of 0 TDS RO/DI water. With the MaxCap I have yet to exhaust the first MaxCap cartridge and I am at 530 gallons and still showing 0 TDS. They claim 3.5 to 4x the life of normal resin for the MaxCap cartridge and the Silica Buster should last for at least 3 MaxCaps so thats somewhere in the 2000 to 2400 gallon range for it!
No comparison.
 
i just talked to spectrapure technical support and asked about their new system and they said that they are not having any problems with testing and if everything works out they should have the new system on the market in 2-3 months
 
is the water quality the same for both system? i was also told that the maxcap di will last about 1200g.
i should of also asked if they are going to make an upgrade unit for existing Maxcap owners when the new system comes out.
 
They have improved the MaxCap cartridge since I bought my new unit 8 months ago. They told me the new cartridge is even better than what I am experiencing but not how much better! The final water quality is probably very similar, with the new system probably having a slight edge but the real savings is in the greatly reduced flush water needs and the longevity of the components.
I doubt if there is an upgrade as it is a completely different design using the microprocessor and completely different components.
 
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