Choosing RODI - Hard Water

[Miss_Bangarang]

I am coming from a multi decade freshwater background from a very different water source, so have never been in a position where I can't just dump water in a tank straight from the tap. I am looking to purchase my first RODI unit for my first saltwater aquarium, and I don't want to buy a unit which can't get the water down to 0 TDS.

Background:
My current area has nasty water issues. As in our faucets corrode and break apart around the spigot after just a couple years. As in your-hair-feels-weird-after-a-shower, and dishwashers-aren't-worth-crap kind of issues. Depending on the test kit and the year, I've gotten results for GH of anywhere between 480 - 770 ppm. I've heard the federal guideline for potable water is 500 or below, so...yeah. I'm a 1/4 mile from a limestone quarry, so a little interesting from a water chemistry point of view, especially considering KH will sit well below 100.

Question:
So my question is, especially to those of you with very hard water experience, what kind of RODI should I be looking at? Not necessarily looking for brand preferences, but more of a general "what can handle this kind of water" sort of guidance. Although if you're in a similar situation and a particular unit has worked for you, I'm all ears. For example, if I get a 4 stage can it remove all the junk and it is more of an issue of how long the filters will last, or will it simply not remove everything from the water and I would need a unit with more stages.

First post, by the way - Yay! :D

 

[Shep]

@AZDesertRat will be able to provide some information, pretty much an RODI expert

 

[ndrwater]

I live in Southern California, where the water is pretty much..... Crap. ...Separates like salad dressing, and TDS over 1000 isn't uncommon at my house..
I do a double carbon block for Chlorine/Chloramine after a sediment filter, double RO membrane and dual DI resin chambers.
I have to flush the membranes every time I make water (couple times a week) and go through about one DI cartridge every 4-5 weeks.
All that said, I get 0 TDS out of my unit no problem.
I use the BRS unit with the additional membrane for 150 per day and buy the DI resin in the 7# bag... Kinda spendy overall, but worth it when you take into consideration the $$$$ I have invested in corals..

 

[AZDesertRat]

More stages aren't better. Fewer, but higher quality stages will win every time. Every filter or stage you add has an associated cost and pressure loss which makes the unit less efficient and drives the cost per gallon up.
The absolute best thing you can do for an RO membrane is a water softener. I found here in Phoenix with extremely hard Colorado and Salt River waters and TDS anywhere between 500 and 1200 it makes a huge difference.
Speak to the folks at Spectrapure, they have been designing and building RO/DI systems for the desert Southwest for over 30 years, it's pretty much all they do. Give them your water quality data and they can come up with just what you need without selling you something you don't.

 

[Miss_Bangarang]

Thanks guys, that points me in the right direction. Unfortunately I'm currently in an apartment, but I'm house-hunting so hopefully a whole-house water softener will be in my future.

 

[cromag27]

Water softener isn't required though. if you want the purest water at the lowest overall cost, then you want a spectrapure rodi with spectrapure filters. some people think they can skimp on filters and buy whatever's cheapest because, well, they're cheap. junk filters may still produce 0 tds water which is what we strive for, but they end up replacing those filters more often.

 

[RunBikeSwim]

Water softener isn't required though. if you want the purest water at the lowest overall cost, then you want a spectrapure rodi with spectrapure filters. some people think they can skimp on filters and buy whatever's cheapest because, well, they're cheap. junk filters may still produce 0 tds water which is what we strive for, but they end up replacing those filters more often.

Please show the data that backs up your statement. How are you quantifying Spectrapure is better than GE and Dow filters in combination with other RODI systems?

 

[beaslbob]

fwiw what makes the water "hard" is calcium and magnesium. the bad stuff for our corals is actually the copper from your pipes.

my .02

 

[AZDesertRat]

I have logbooks of data. Spectrapure researches, tests and only sells low micron absolute or near absolute sediment and carbon block filters for the best results. It only makes sense, protect the carbon block with a quality sediment filter and it will last long never and work better. This in turn protects the RO membrane so it works better and lasts longer so the DI lasts longer and works better.
Many vendors sell inferior filters about as effective as a screen door. Did you know you can see 40 microns with the unaided human eye? Which protects better 0.2 or 0.5 microns absolute or 5-10 microns nominal? They have been researching just that for over 30 years so we the end user doesn't have to. My switch from Watts Premier to AWI was a big cost savings but the switch to Spectrapure was a dramatic savings all together different. I would never go back.

 

[RunBikeSwim]

I have logbooks of data. Spectrapure researches, tests and only sells low micron absolute or near absolute sediment and carbon block filters for the best results. It only makes sense, protect the carbon block with a quality sediment filter and it will last long never and work better. This in turn protects the RO membrane so it works better and lasts longer so the DI lasts longer and works better.
Many vendors sell inferior filters about as effective as a screen door. Did you know you can see 40 microns with the unaided human eye? Which protects better 0.2 or 0.5 microns absolute or 5-10 microns nominal? They have been researching just that for over 30 years so we the end user doesn't have to. My switch from Watts Premier to AWI was a big cost savings but the switch to Spectrapure was a dramatic savings all together different. I would never go back.

Please quantify your data of Spectrapure filters in comparison to Dow or GE filters. How did you test? What savings are you seeing? All I see from Spectrapure fans are pure marketing verbiage without actual data. Lets see your data so we can see if Spectrapure is the best or just another overpriced, overhyped product.