need to know more about RODI units!

[TimmyG]

so I know nothing about how to set them up or where to even get the unit from at that! please enlighten me with what I should find out about before getting one.

I was told that I can use the same unit for water changes and evaporation for both my salt water and fresh. let me know!

[David Grigor]

thefilterguys.biz Excellent customer service, here in duluth. Also look at the twopartsolution.com rodi unit in Golden Valley. Good price and uses quality filters.

If you look at cheap units such as water general on ebay. While the initial cost looks attractive. It wll cost you more because you will go through DI resins much quicker because the membranes are not 97+% rejection rate. For the most part, if it doens't mention the brandname of the membranes and less than 97% rejection rate then it's probably not a good one. Units with a Filmtec 75gpd membranes are a safe bet.

[Zibba]

I picked up this unit from thefilterguys.biz -

$160.00 - OCEAN WAVE+ FIVE STAGE 75 GPD RO/DI

and I added this - $14.00 - CHLORAMINE FILTER UPGRADE

My recommendations are to set up the unit next to your laundry - using the cold water faucet only! I would avoid piercing your copper pipe under a sink since the adapter can leak. Another thing that would be helpful (which I will add soon) is the dual TDS (total dissolved solids) meter which will tell you how effective your filter is.

Yes - you can use this water for replacing your evaporation and your new saltwater make ups. Essentially you want any amount of water that will go into your tank to come from this unit. In the long run - you will easily save yourself a lot of money.

There will certainly be people who will attempt to argue that RODI is unnecessary....please don't listen to them. However, I will say that RODI units do reject a lot of water - usually about 5 gallons of waste to 1 gallon of purified - but this "waste" water can easily be used for watering plants, washing floors, etc.

One last thing - DON'T set this up to top off your system through float switches/valves - there are many stories of people's valves getting stuck on resulting in hyposalinity or a flooded room.

[dougers31]

How safe is this water for drinking purposes, etc?

[Goldpony75]

perfectly safe for drinking, it just dont taste the best unless you get it before it goes through the DI stage.
How safe is this water for drinking purposes, etc?

[David Grigor]

Only in very extreme situations is drinking RO/DI unsafe. Most don't drink it because of taste for the most part fine to drink if you wish. It's really true for too much of anytype of water but since RO/DI has not mineral content it can be more so.

In extreme cases where you are on a hunger strike and only drinking ro/di without getting minerals from food, extreme excerising where loosing lots of liquids and replaceing with ro/di, or drinking lots at a time without going to the bathroom you can die from water intoxication. But is the VERY EXTREME case and not very likely.

You may or may not recall a while back a radio station did a contest to hold your wee for a wii where contestants where to drink bottled water and try not to go to the bathroom. A lady died from water intoxication because it diluted her electolytes in the body.

Under normal circumstances though it is perfectly safe.

More info if you'd like:

http://en.wikipedia.org/wiki/Water_intoxication

[TimmyG]

well I was looking at putting the unit by the water softener so that I would be using the water before it went through there. would that be a good idea or do I want it after that?

[hypertech]

Give the filter guys a call. They will answer all your questions.

From what they told me, its better to get the water after the softener. That's where I plumbed mine in.

[David Grigor]

After the water softener.

[TimmyG]

ok, I'll have to call them and see what they say I'll need. how many stage does everyone think I need?

[hypertech]

5 - you want the DI but probably don't need dual DI.

I got the one with the little horizontal DI because I don't make much water and if it doesn't cost much more to upgrade to the canister if I need to later on.

[David Grigor]

Long term you do want the dual DI. Outside of replacing the membrane every 3 years or so, the resins is the second highest maintenance cost. Anything you can do to prolong tme the better.

You will find that your TDS reading will start to rise before the DI is fully exhausted. With a dula you can get another 30days ( or more if using small quantities ) so out of the first DI until completely exhausted while still getting 0 tds because the second DI takes over.

When TDS after first DI = the TDS after the membrane then its fully exhausted and move the second cartridge to the first and refil the old one.

Me being lazy and having extra cannisters around I have 3 hooked up.

Also, don't rely on the color changing resins. You want the tds meter. The resins will change colors before exhausted and you will end up replacing sooner than need be. Should be using TDS to know when exhausted.

[patent]

Long term you do want the dual DI. . . . Me being lazy and having extra cannisters around I have 3 hooked up. Cool, I'd love to have that nice of a setup.

That said, a dual DI is a luxury, and if cost is an issue you can start with a single DI and add more later as you want ($35-40 for a DI add on). I agree on the tds meter, my resin color changed long before the tds meter read a change, so go with the tds meter. I now use the color change as the point to start testing tds (probably way too lazy on my part).

I'd also make sure that the DI resin canister you get with your system is one that is refillable, and buy an extra packet of DI resin at the time of purchase. When the first runs out you have more on hand, so you don't really need that dual setup. Sea Monkey at twopartsolution.com also sells some, so he would be a good local source for refiills if needed in a hurry.

patent

[hypertech]

This is the cheapest place I've seen the inline meters:

http://cgi.ebay.com/Dual-Inline-TDS-meter-Reverse-Osmosis-RO-DI-only-26-95_W0QQitemZ250150702829QQihZ015QQcategoryZ46310QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem

[patent]

That is the one I'm using, works well enough.

patent

[Goldpony75]

Check out this tds meter, http://www.airwaterice.com/product/SENNODUALTDSMETER
This is the one i use and it works great, it show both in and out at the same time and will alert you when your rejection rate is less then 80% and its backlit. plus free shipping, i got mine in two days by usps priority.

[David Grigor]

Like I explained earlier the dual does save you money in the long run without every compromising water quality. It's just a standard 10" housing you can usually pick one up for like $10 ( it doesn't have to be clear since best to use tds meter not color changing ). With a single DI, you will be changing it out becuase TDS reading above 1 but it isn't fully exhausted yet. When your figure an extra 30days you can get out per change that adds up over the coarse of years to easily pay for itself. Since


I'm planning to get a second tds inline, currently I'm measuring after 1st DI and the last DI, I want to also add a inline tds to see the measurement before membrane and after membrane so I know how it's performing and when may need replacing.


Since I'm in it for the long haul and also have a seperate ro drinking water system. Because our water has such high iron content, I change my sediment every 3 months. Since they are cheap I buy a couple dozen at a time. Also buy the carbon guzzlers and di resin in bulk and keep an extra membrane on hand. This way, there is no emergency I have replacements for everything on hand ready to go. Make an order once every couple of years....... Had been getting it all from filterguys but now since qty discounted will be getting from ryan at twopart.

[hypertech]

Check out this tds meter, http://www.airwaterice.com/product/SENNODUALTDSMETER
This is the one i use and it works great, it show both in and out at the same time and will alert you when your rejection rate is less then 80% and its backlit. plus free shipping, i got mine in two days by usps priority.

Thanks for pointing that one out. I just ordered one.

[David Grigor]

I'll probably get one of that style to when ready to order......

[wkjames]

Long term you do want the dual DI. Outside of replacing the membrane every 3 years or so, the resins is the second highest maintenance cost. Anything you can do to prolong tme the better.

You will find that your TDS reading will start to rise before the DI is fully exhausted. With a dula you can get another 30days ( or more if using small quantities ) so out of the first DI until completely exhausted while still getting 0 tds because the second DI takes over.

When TDS after first DI = the TDS after the membrane then its fully exhausted and move the second cartridge to the first and refil the old one.

Me being lazy and having extra cannisters around I have 3 hooked up.

Also, don't rely on the color changing resins. You want the tds meter. The resins will change colors before exhausted and you will end up replacing sooner than need be. Should be using TDS to know when exhausted.

I think David's advice is right on. I bought mine from ebay. Here's a current link: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120118639490&ssPageName=MERCOSI_VI_ROSI_PR4_PCN_BIX_Stores&refitem=120013117047&itemcount=4&refwidgetloc=closed_view_item&refwidgettype=osi_widget
Purchased a year and a half ago, I bought the float valve and a TDS meter, plus an extra bag of DI media, and upgraded to all clear canisters for the big 3 and upgraded to dual DI cannisters. I have been really happy, not needed to change filters yet, and still measure 0 ppm. Delivered for about $160 including all of the extras, upgrades, and goodies. I definitely recommend getting one with a holding tank, and a sink faucet. Also, if I need to mix up some water for anything like quarantine, I don't have to plan an hour in advance. Not worth the savings to skip it. I couldn't be happier. BTW, I guess someone in the club does this for a living, so I don't mean to offend. I'm sure what you sell is great, I'm just saying what I bought before I was a member. I'll be likely to buy filters locally when my TDS begins to go up.

The water is SO much better to drink and cook with than city water. I plumbed mine to get the water for the sink after the DI. I'm not sure what the others are talking about as far as the taste before vs after the DI. Everyone who visits raves about how good it is, and it makes nearly crystal clear ice cubes.

[TimmyG]

The water is SO much better to drink and cook with than city water. I plumbed mine to get the water for the sink after the DI. I'm not sure what the others are talking about as far as the taste before vs after the DI. Everyone who visits raves about how good it is, and it makes nearly crystal clear ice cubes.

they are talking about the bad water that gets filtered out. they where talking about uses for it like watering the plants or if it was safe to drink. they where not talking about the DI water!

[hypertech]

OK, I just got that meter, and here's what it says.

Tap - 860
RO - 5-8
DI - 0

Does that sounds reasonable?

[Goldpony75]

Well to go from 820 to 5-8 is huge that will really make your di last. and zero is what you want to shoot for.
OK, I just got that meter, and here's what it says.

Tap - 860
RO - 5-8
DI - 0

Does that sounds reasonable?

[David Grigor]

You tap reading has to be off. Here in Brooklyn Center Tap is closer to 300ppm.

That is 99.9% rejection which I don't think is possible from just RO membrane.

[hypertech]

I don't know if Brooklyn Center and Brooklyn Park get their water from the same place.

I just checked it again and the lowest number I saw was 840.

I wonder if the piece of crap water softener that came with house is elevating it?

[David Grigor]

Are you putting the tap water in a cup to measure ? If so and haven't done so already be sure to rinse the cup real well with ro/di water first to be sure the cup is nice and clean, it can and does make a difference with your readings.

[hypertech]

No, its an inline meter, so I hooked it up to the supply line.

[Goldpony75]

any way you can get a sample of your water before the water softner? like at the bypass.
im not exactly sure how water softeners work but arent they basicly buffering the water? hence adding something to it?
im just guessing so correct me if im wrong.