new ro di deal

I am looking to upgrade my ro/di system.
i found these two on ebay, either of them any good?\

i like the first one cuz it comes with 3 years of filters, but the second has a built in uv light,

AQUARIUM II REVERSE OSMOSIS WATER FILTER 7 STAGE RO/DI on eBay.ca (item 250782001380 end time 04-Mar-11 17:51:45 EST)


7 Stage RO+DI+UV Reverse Osmosis System Water Filter on eBay.ca (item 160546350138 end time 16-Mar-11 15:26:01 EDT)

any input

 

What is your existing system? You might be better off upgrading the individual filters and adding a decent DI stage...

 

search spectrapure, they are members here and, to the best of my knowledge, produce the best personal RO/DI unit at the best possible price.

 

my current one is a coralife 24gpd ro unit. for the cost of upgrading filters and the add ons i may as well pick up a new system. i was wondering about those units or order one from bulk reef supply

 

No and No.
For one they both use horizontal inefficient DI chambers.
Horizontals channel and short circuit and usually do not hold as much resin as the standard 10" canister and refillable cartridge type with 20 oz of resin in a bottom up flow configuration so all resin andwater come into contact with each other.

Typical of most ebay systems they tout "7 STAGES" like its the best thing since sliced bread. In reality 7 crappy stages does not equal 4 good stages. Never ever look at how many "stages" a unit has, instead look at what the stages contain.

Lets look at a real reef quality RO/DI compared to one of these:
Stage 1- a good reef quality system will contain a 1 micron or less prefilter, and an absolute rated prefilter is much better than a nominal rated prefilter. Notice how the one says from 20 microns down to 5 microns? What that means is it contains a cheap nominal rated prefilter that may trap large things in the 20 micron range and it may trap say 10 or 20% of the particles as low as 5 microns but no guarantee. The good system will havd an absolute rated prefilte that will trap 99+% of all particles down to and including its rating, huge difference.

Stage 2- A good reef quality RO/DI will have a single 0.5 or 0.6 micron, near absolute rated solid carbon block such as the Matrikx +1. The first one you linked to has a granular carbon cartridge which has absolutely no place in a RO/DI system, it turns to dust and plugs or fouls whatever is downstream of it rendering them both useless. Carbon depends on its billions of tiny microscopic pores to adsorb chlorine and VOC's, if the prefilter is crap and passes solids through or you have granular media that breaks down to dust you have no pores left as they are all plugged.

Stage 3- the good system will have the RO membrane in this position since I already mentioned two carbons are not necessary when you include one high quality carbon block preceded by a high quality low micron prefilter, why waste a canister and cartridge when you are paying for it? The cheap systems include a second carbon in this position since the first one is shot already due to plugging or in the case of GAC only has a useful life of 300 gallons total, thats 240 waste gallons and only 60, yes 60 treated gallons.

Stage 4- the good system will have a full size 10" vertical canister with a refillable 20 oz cartridge in this position. The cheap system will have the membrane in this position. Also note the cheap systems often do not reveal who manufacturers the RO membrane and in many cases its either an imported knock off not even approved by the ANSI/NSF for drinking water use in the USA or it could be a Nano Filter rated at only 90% rejection and not even a Reverse Osmosis membrane rated at 96-98% rejection. Big differences .

Stage 5- well there should not be a fifth stage unless you want to add an additional ful size vertical DI for excellent water quality or if you use the unit for drinking water too you could have a DI bypass installed and use a GAC taste and odor filter in this position so you get RO/DI for the tanks and RO only with a final polishing filter for drinking.

Stages 6 and 7 are not even worth discussing since they are a sales gimmick is all to make a crappy system sound cool.

Just because one of them gives you a bunch of extra replacements isn't really a deal since they are low quality, probably about equal to a screen door when it comes to filtration. The other again includes things like UV and a horizontal DI again which you don't want or need.

I have found over the years you really do get what you pay for with RO and RO/DI systems. I will say I do own a H2O Splash for my drinking water RO but not for my reef RO/DI, its too critical and of a different quality.

Take a look at the Spectrapure units already mentioned by others and notice the differences.

They even have a sale flyer here:
Untitled Document

Look at what you get for your $199, a 0.5 micron absolute rated prefilter, a 0.5 micron 20,000 gallon carbon block, a treated and tested 90 GPD RO membrane that will be better than 98% rejection, a full size 20 oz vertical refillable DI with custom blended reef specific DI resin, usually mixed and packaged the day it ships, a TDS meter, a pressure gauge, a capillary tube flow restrictor and much more. I don't think you can find anything even similar for twice the price.

 

Wow! Excellent info! Way to break it down

 

MaxCap 90gpd RO/DI => $349.00

MAXCAP RO/DI SYSTEM

Upgrading existing unit => $180.48

membrane => $45.00
.5u sediment => $16.99
.5u carbon => $19.49
MaxCap dual DI => $99.00

You can see a generally equivalent upgrade is less expensive than the full unit by half...

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Just got finished installing this...

 

Actually the MaxCap is $259.
Untitled Document

A hand tested and guaranteed 98+% membrane is $45, a matched capillary tube flow restrictor is $5, a 0.5 micron prefilter and carbon block are on sale for $25, the MaxCap dual DI with one TDS meter is as you pointed out is $99, an additional dual inline TDS meter to measure the tap and RO only water is another $30 and an inline pressure gauge kit is $15.

Thats $240 and you still have the same housings and fittings whatever quality they may be and there are lots of different qualities on the market. The cost to upgrade is almost always much more than buying the correct unit to begin with.

 

hmm i love the unit, cept i live in canada. the shipping will run me 100+.