RO/DI Help Calling All Experts

I was given a Whirlpool WHER25 RO filter from Lowes. The guy at the pet store suggested to go with a Spectrapure unit while the owner said the Whirlpool was fine. What are the pros and cons of both units? What should I buy for the best bang for my buck?

 

This one is for AZdesertrat. Please help my friend out.

 

I actually bought that one because I needed one and lowes was close. It was also only like 140 bucks... After reading the manual for that one I found that the rejection ratio (amount of water used to make one good gallon) was 6:1. That basically meant that for my 210 gallon system I would need to make 20 gallons a week.... at 6:1 it would be wasting 100 gallons of water to make 20 gallons of pure. I immediately took it back and went with spectrapure. They actually have a sale pretty much all the time and I got a 3 stage unit for about 150 bucks. I had to buy a booster also which was about 100 bucks but you might not need one of those depending on your water pressure. It runs best between 40 - 80 psi. Our house runs at about 38psi so obviously I needed the booster. The rejection rate is around 2 or 3:1 on this unit which is much more efficient. I would strongly advise getting the spectrapure unit and if you would like I still have the email with the sale flyer that will save you about 100 bucks per unit. PM me with an email address and I can send that to you. Just my opinion based on experience with both of those units... hopefully that helps!

 

Adjusting the waste ratio of any system is as easy as changing the flow restrictor from a fixed type to a capillary tube type and trimming it according to your exact conditions.


Thats not the major problem with the Whirlpool system though, they use non standard RO membranes which is the problem. Most all units you see use a standard Dow Filmtec 1812 configuration membrane and the Whirlpool, some Sears and some Watts Premier systems if I remember right use a non standard 1810 membrane. A standard 1812 will not fit in a 1810 or Whirlpool RO membrane housing and vice versa so replacement is tough in the future.

I am a big fan of Spectrapure products too but tgood, you need to take the time to adjust your waste ratio to 4:1 which in the normal waste ratio for most waters so your membrane lasts and works best. Unless your tap water TDS is extremely low, say 100 or less the waste needs to be 4:1 and this is why Spectrapure supplies capillary tube flow restrictors so you can adjust or trim it as necessary.

 

Can you go in to detail why spectrapure membranes, di resins, carbon, and prefilters are better than others?

 

The purpose of sediment, particulate or more commonly called prefilters and carbon blocks are to protect the expensive RO membrane which is the workhorse of the system.
If you filter things out before they reach the membrane it will last longer and work better which results is fewer replacements over the life of the system and a lower overall cost of ownership.

I do not work for or represent Spectrapure in any way but I think my profession as a wtare treatment plant operator and manager plus personal experience allows me to answer this question. That and I have personally toured their facility many times and spent quite a bit of time quizzing their staff and paying attention to the answers to my many questions. We in Phoenix have been fortunate enough to have them speak at club meetings and reef get togethers too and its been very informative to say the least.

Spectrapure has done 25 years of testing in Tempe AZ not only with much higher than normal TDS waters straight from the tap but they also have large tanks in which they can mix up stock solutions with known amounts of various contaminants for more scientific testing and monitor or log the results in databases. The testing has resulted in their use of low micron range filters as the standard in all their reef systems. Not only this but they have found absolute rated filters perform better than nominal rated filters in the same micron ranges and are worth the slight extra cost. The reason you have a prefilter is to protect the carbon blocks billions of tiny microscopic pores so they can adsorb chlorine and volatile organic chemicals. If the prefilter does not perform well it passes particulates and colloidal materials on to the carbon fouling or plugging it so it is useless.

So Spectrapure offers absolute prefilters in 0.2, 0.5 and 1.0 micron sizes and carbon blocks in 0.5 and 1.0 micron ranges so they do the best possible job of protecting that membrane so it can do its job of removing TDS.

Most all vendors use dry, untested, off the shelf RO membranes so you get what you get and rarely are membranes performance guaranteed. While Dow Filmtec, the most popular brand by far, claims 96-98% rejection its usually on the lower side of 96-97% out of the wrapper based on tens of thousands of membranes tested over the las t25 years according to Spectrapure. This tesing has resulted in a special proprietary treatment process known only to them which improves both the GPD and the rejection rate so you get a better membrane and which results in longer DI resin life. What they have found is for every 2% they can increase the rejection rate you get DOUBLE the life out of your DI resin, so now you have longer membrane life and longer DI life. When you opt for their "Select: series high rejection rate RO membranes you also get a written performance guarantee which states it will do better than 98% with a persons name on the membrane and what it tested at in their lab. You don't get that performance guarantee anywhere else. My personal MaxCap UHE system is 3.5 years old and the rejection rate is still 99.35% to this day.

Next they tell me they were not happy with the performance of most DI resins on the market so they set up a test lab and started testing every brand and blend they could get their hands on. They found if they blend their own resins in house they have better quality control and better performance and can guarantee fresh resin. I have been told their resins are often blended and packaged the same day they are shipped so it does not come any fresher. They are also packed in vacuum sealed mylar bags so should stay fresh for longer periods of time than others in a plastic bag. Now you have even longer DI life and even better performance so the cost of ownership over time has gone down even further.

What all this amounts to is they build a RO/DI system from the ground up, starting from the prefilter, to the carbon block, membrane and DI all the way through to the capillary tube flow restrictor, name brand fittings and housings, brackets, gauges amd meters so it performs at its peak, you can monitor its performance and you can do things to improve its performance like trim the flow restrictor for optimal waste ratios or monitor the pressure ,TDS and temperature and change things accordingly. There is no afterthought, they use only the best from start to finish so you get the best, most efficient and lowest cost to operate system on the market.

Every thring I have said or implied here is on their website under headings like FAQ, Tech Support and Education and can be found at SpectraPure Water Purification Products . Companies don't stay around for 25 years if they don't stay on top of things and provide the very best.

 

Thanks guys for all the info... SpectraPure it will be then.

 

By reading this I think I am gonna give spectraPure MaxPure40GPD a try. thanks!!

 

You would want the 90 GPD unit.
MAXPURE MPDI SYSTEM

There is no advantage to a lower GPD and lots of disadvantages like it takes over twice as long to make the same amount of water.

 

whenever i see a thread about ro/di i almost always read it because i always learn something from AZ haha