RO or RO/DI??

[DJM28064212]

I was thinking about investing in an RO filter, but I know there are also RO/DI filters. The question is if I get an RO/DI filter should I still run a Phosban reactor with media, or would that just be overkill. Also, ho like do the DI filters work for, in other words would it be better to save the extra 20 dollars and just run a Phosban reactor??
I was looking at the ones at buckeyefieldsupply.com
Thanks Doug

 

[surfnvb7]

you gota get an RO/DI filter, to pre-treat your water before it goes into the tank. just recently, last fall, the town of blacksburg sent out a notice saying they are treating the water supply with chloramine (deadly to fish/corals). the RO/DI will take out just about all of those chemicals they add at the water filtration plant. including any phosphates and silicates (hopefully), which i'm sure is released in some of chemical by-products. i had terrible algae problems in my planted tank due to high phosphates in the tap water. but the purpose of the RO/DI is to get rid of those other things in the tap water besides just phosphates/silicates.

the phosban reactor will only help to take out silicates/phosphates that are in the main tank water, usually caused by decaying food matter.

IMO, you should get both.

here is where me, my girlfriend, and several other NRV club members have gotten their RO/DI filters from: http://cgi.ebay.com/AQUA-SAFE-MAXIM...itemZ4426395068QQcategoryZ20684QQcmdZViewItem

this particular model, comes with a TDS meter and PSI guage that are helpful to have around. also has the water holding tank (very useful), some other adapters etc.

only real turn off about the system is the horizontal DI filter. which isn't a big deal as long as you stir up the beads every month or so. if you end up not liking it down the road, you can always purchase a seperate vertical DI stage.

 

[CaptainDave]

what Alex said.

 

[manderx]

yup. and if you do alot of reading, there are a few guys who beat up every thread talking about the membranes different models use. on paper, the DOW filmtec 75gpd has a higher rejection rate (98%) than the 100gpd membrane the cheaper units use (90% or something). so on paper, if you have 100tds in your tapwater, 2 will make it past the 75gpd membrane while 10 will make it past the 100gpd membrane, which means it'll tear up your DI faster. i don't know how true this is in the real world. dave and jc both have the 100gpd membrane and have been getting fantastic results, with post membrane TDS better than my 75gpd filmtec membrane and noticably faster water production.

make sure you get a unit with an autoshutoff (or get it separate and add it yourself). a float valve in conjunction with the autoshutoff to shut it off when the bucket is full is the most important thing you can do with an RO.

 

[surfnvb7]

in that link, the system comes with an auto-shut off valve, which is a must like matt said. the holding tank says it is 4.4g volume, but in reality it only holds about 2.5g, not a big deal.

only other thing that isn't top notch, compared to the expensive systems is the pre-RO filter canisters are not clear. i recently changed out my pre-RO filters and they were really bad looking, mostly brown. i left them in way too long. and that can damage your RO membrane. but ya just gota get used to changing them out on a routine basis.

my TDS from my tap water reads about 70-80 (maybe higher). after my RO its like 4-5. and after the DI its zero. so unless my TDS meter is crap, I'd say my system (w/ the 100gpd RO membrane) is just as good as all of those expensive models. ya just gota remember to change out your pre-RO filters, and DI beeds to keep it running at top performance.

it really is an excellent package, considering all of the stuff that comes with it. more bang for your buck so to speak.

 

[Shivaji]

So what's the poop on flushing out your membranes ? Some people say it is essential to extend the life of the membrane, and others say it doesn't do a thing. Not that the flush kit is expensive, considering everything else.

BTW, Alex are you going to be making a trip to Richmond anytime soon ? Marvin had promised to hold a copperband for me for pickup last Thursday, but when I showed up - he had forgotten all about it. He promised to send one out with the next person coming this way.

 

[surfnvb7]

<a href=showthread.php?s=&postid=7503130#post7503130 target=_blank>Originally posted</a> by Shivaji
So what's the poop on flushing out your membranes ? Some people say it is essential to extend the life of the membrane, and others say it doesn't do a thing. Not that the flush kit is expensive, considering everything else.

BTW, Alex are you going to be making a trip to Richmond anytime soon ? Marvin had promised to hold a copperband for me for pickup last Thursday, but when I showed up - he had forgotten all about it. He promised to send one out with the next person coming this way.

the model i showed in the link, also has the flush kit installed next to the auto-shut off valve. no idea if it *really* works, i just do what the directions say.

hmmm, wasn't planning on making a trip to richmond any time soon. how soon were you thinking about?

 

[Shivaji]

<a href=showthread.php?s=&postid=7503332#post7503332 target=_blank>Originally posted</a> by surfnvb7
hmmm, wasn't planning on making a trip to richmond any time soon. how soon were you thinking about?

I don't know - he was getting in some that day at 4 PM but I could not wait that long as I had to get back to bail out my dog from the kennel by 5:30 PM. Maybe in a couple of weeks, as I wanted to make sure it was eating OK before I got it, which is why I had called him three weeks ago and asked him to hold one for me.

I will give him a call and see what he says ...

 

[Cuby2k]

I am sure this is discussed somewhere on these boards, but I have looked until my eyes water and I can't seem to find a good discussion. Should an RO/DI system be upstream or downstream from a residential water softner?

Not trying to hi-jack your thread DJM, just hoping to add to it.

 

[surfnvb7]

<a href=showthread.php?s=&postid=7504451#post7504451 target=_blank>Originally posted</a> by Cuby2k
I am sure this is discussed somewhere on these boards, but I have looked until my eyes water and I can't seem to find a good discussion. Should an RO/DI system be upstream or downstream from a residential water softner?

Not trying to hi-jack your thread DJM, just hoping to add to it.

any particular reason why you would want to? i would think that some people who have wells (as in the case out here in the mountains), if the water is subject to a lime deposit, they wouldn't have to add that much kalk/baking soda to their tank water in order to get the dkh up, as with some city water. ??

 

[Cuby2k]

The only reason I would want to connect the RO/DI unit downstream from the water softener is convenience. The water throughout the house is soft and to run another line to a new sink just for the hard water will be a pain.

But if that is the right way to do it . . . .

 

[manderx]

back in the day everyone said to put the RO before the softener, i think mostly to save wear and tear on the softener itself since for every 1 gallon of RO you make, that's 3-4-5 gallons of softened water down the drain. but nowadays i'm seeing more people say that the salts from the softener are easier for the RO to exclude than the calcium it replaces.

if it was me, it would probably depend on how hard your wellwater is. i used to be on wellwater that was about 400tds and my membranes lasted a couple years before it slowed down from calcium deposits. i never flushed, don't know if that would have helped (still trying to conceptualize exactly how the flush would help after taking a few membanes apart). a couple years was good enough for me and i got good enough water out of it. dunno how expensive a softener is to recharge, so i can't really say at what threshold tds level i'd recommend using softened water to feed the RO. if it was pennies per hunded gallons i'd probably use softenend water.

any particular reason why you would want to? i would think that some people who have wells (as in the case out here in the mountains), if the water is subject to a lime deposit, they wouldn't have to add that much kalk/baking soda to their tank water in order to get the dkh up,

the ca/alk in the wellwater is completely insignificant compared to kalk (which everyone should be doing already for all their topoff). the prob with wellwater (like all tapwater) is who knows what else is in there (nitrate/phosphate/chemicals). back when i used wellwater, mixing up saltwater would always leave alot of crust in the bin. so the calcium/alk in the wellwater probably did more harm than good.

 

[manderx]

The water throughout the house is soft and to run another line to a new sink just for the hard water will be a pain

hooking the RO before/after the softener shouldn't be any different in terms of work to hook it up. no need to plumb it to a sink. just use a saddle valve (or threaded fitting of some sort if appropriate) from whichever side of the softener you want to draw from, and run however much 1/4" poly tubing to where you keep the RO.

 

[Cuby2k]

<a href=showthread.php?s=&postid=7507446#post7507446 target=_blank>Originally posted</a> by manderx
back in the day everyone said to put the RO before the softener, i think mostly to save wear and tear on the softener itself since for every 1 gallon of RO you make, that's 3-4-5 gallons of softened water down the drain. but nowadays i'm seeing more people say that the salts from the softener are easier for the RO to exclude than the calcium it replaces.

Good response, I appreciate your perspective and I think that makes good sense.