RO/DI Filter Replacement

[amr952]

Good Morning,

I have an older RO/DI unit from TheFilterGuys and it is that time of year again to replace the filters. Normally I have always replaced the filters with the standard 4 stage filter kits (1 Sediment, 2 Carbon and DI). This has worked well for me in the past but I have recently moved to a new house and we are now on well water. The water seems fairly clean with only 30-40TDS. I read online that when you are on well water you have less of a need to have two carbon blocks so I have considered switching to 5 micron sediment, 1 micron sediment, .6 micron Carbon and then DI. Would that make sense or should I stick to 2 carbon blocks?

Also my RO filter is going on 8 years old now but it still seems to be working great. 30 going in and never over 4 coming out (Usually 1-3). Safe to keep using?

I think I also need to add a booster pump. I see the pressure range from 25-60. Looks like my well pump pressure switch has a fairly large range.

Thank you for your advice in advance!

Andrew

[azjohnny]

40 going in and 4 going out is a poor ratio, turns out to be only a rejection rate of 87%.

If you have a quality sediment and carbon filters you only need 1 of each. 5 micron is too big of a micron size, don't go larger than a 1.0

I would go with 2 DI cartridges, 1 sediment and carbon. I would invest in a booster pump and depending on your membrane you might need a new one, your rejection rate shouldn't be less than 96%

I have over 100 psi going to my Spectrapure Maxcap and I have a 99% rejection rate and produces 160 gpd from a 90 gpd membrane due to the increased pressure

[amr952]

I actually had considered getting another cartridge so I could have two DI stages. So you are saying I should just run a 1 micron sediment filter and maybe a .6 carbon and just leave the other empty?

Are you getting 100PSI out of an 8800 booster pump?

Thank you!

[shifty51008]

I would replace the membrane if your getting that low of rejection rate. And also add a booster pump so that you always get at least 60-90psi.

But i would run 1 sediment, 1 carbon, and use the 3 container as a 2nd di stage unless you have chloramines then use gac.

I would also sanitize the system which you should do once a year anyway

[amr952]

Makes sense, I will purchase another RO membrane. I cannot really use the 3rd container as a second DI stage since the first 3 stages are all linked as one before the RO stage. But I can easily purchase another canister and run two DI stages that way.

I assume the 8800 booster pump is what everyone is using?

[shifty51008]

You have a pic of your unit? Usually there is a way to re route the lines so you can use the 3rd canister as a di stage.

The 8800 pump is what you want, make sure to buy the kit so you have the power supply and such

[amr952]

I have Ocean Reef +1 from http://www.thefilterguys.biz/ro_di_systems.htm

Ok cool, BRS has the 8800 kit for 135 today because of their labor day sale. Seems like a good deal.

[azjohnny]

Originally Posted by amr952

I actually had considered getting another cartridge so I could have two DI stages. So you are saying I should just run a 1 micron sediment filter and maybe a .6 carbon and just leave the other empty?

Are you getting 100PSI out of an 8800 booster pump?

Thank you!

I wouldn't run a smaller micron size at the carbon as the sediment other wise the carbon will than act as a sediment filter for the <1 micron size. I either run an equal size or the sediment is smaller

I present run

sediment- .2 micron
carbon - .5 micron

I don't run a booster pump, my incoming water pressure is that high. When I have run a booster pump it was the Aquatec 8800

[shifty51008]

Thats a good deal on the booster pump.

As for the rerouting the filters that is a no go sorry, most units i see have a space between the 2nd and 3rd container. But you could buy a 2 canister bracket and take the 3rd canister off your unit and your di canister and put them both on the 2 bracket peice. May as well use it sence you already have it

[Jimmer12]

I don't see why you couldn't make the third canister a di stage. Just take apart the heads between the 2nd and 3rd, route the line up from the second stage to the membrane, turn the third stage 90 degrees and run the line from the membrane down to the third stage and then it becomes 2 di stages in series.

[amr952]

I am sure that would have worked. I just went ahead and ordered the dual DI hit from BRS and I am going to use my single to run GFO. Also picked up the booster pump along with filters.

Thank you for the advice everyone!

[Johnseye]

Originally Posted by azjohnny

40 going in and 4 going out is a poor ratio, turns out to be only a rejection rate of 87%.

If you have a quality sediment and carbon filters you only need 1 of each. 5 micron is too big of a micron size, don't go larger than a 1.0

I would go with 2 DI cartridges, 1 sediment and carbon. I would invest in a booster pump and depending on your membrane you might need a new one, your rejection rate shouldn't be less than 96%

I have over 100 psi going to my Spectrapure Maxcap and I have a 99% rejection rate and produces 160 gpd from a 90 gpd membrane due to the increased pressure

How'd you calculate the rejection rate? Anytime I see a +1 on the far right DI cartridge I change my 2 DI filters per Spectrapure's advice. I'm leery they just want to keep selling the filters, but I also don't want any silicates in my tank.

[Opus123]

Originally Posted by Johnseye

How'd you calculate the rejection rate? Anytime I see a +1 on the far right DI cartridge I change my 2 DI filters per Spectrapure's advice. I'm leery they just want to keep selling the filters, but I also don't want any silicates in my tank.

The OP said he had 30 tds going in and 4 coming out at the RO membrane. 4/30 gives you .13, so 100 minus .13 gives you the 87% rejection rate. If the RO unit was working efficiently he should be getting 1 or below after the RO membrane based on the low tds of the tap water.

[azjohnny]

How'd you calculate the rejection rate? Anytime I see a +1 on the far right DI cartridge I change my 2 DI filters per Spectrapure's advice. I'm leery they just want to keep selling the filters, but I also don't want any silicates in my tank.

Processed water TDS divided by feed water TDS

[amr952]

Yeah I agree 87% percent is not good, I did not purchase a new RO Membrane since I wanted to see if my rejection rates improve with he booster pump. I was seeing pressures as low as 20psi. Booster pump and Dual DI will be here Monday.

[shifty51008]

On a 8 year old system i would imagine the membrane ia shot, mine usually last 3 years before my % starts to drop.

[NotYoNano]

.5 micron sediment and carbon from marinedepot(spectrapure brand), buy 50gpd ro membrane for less waste water and using less di resin over time, buy 100gpd ro membrane for more waste but more output and having to replace di resin more often(high silicate absorption membranes available too), get some silica resin for 1 canister(i use filterguys), then an inline tds meter(if dual;first goes after ro membrane) and then 2 canisters of di resin.(silicates will slip through di resin, thus you want a separate canister of silica resin before the di) You'll then just need a few plugs and hose. You'll spend as much as the starter unit's from pretty much any vendor, but you will get better quality water vs resources ratios.

(above is a pre-typed blurb, .5 microns all the way though )
Since adding a 2nd .5 micron carbon block, I find my tds from ro is now 3 instead of 13-15. So it's definitely welcome to extend the life of the di chambers.

[jjoos99]

I recently burnt through a di resin refill in just 60 gallons of water. My well water is at 460 with 30 coming out of the ro. comes out to be about 93%. I bought this unit used a good year or so ago so I would think I should try a new membrane. Cant keep the di changed fast enough the way it is going. I have a booster pump but it is running about 50 psi.
Jeff

[scubadan206]

.

I would also sanitize the system which you should do once a year anyway[/QUOTE]

How do you recommend sanitizing an RODI system?

[Buckeye Hydro]

You can find instructions to sanitize your system here

Russ

[Buckeye Hydro]

I wouldn't recommend a 0.5 or 0.6 mic carbon block with well water. Here an instance where you can save some money - go with a 5 mic carbon block. Assuming you don't have a chlorine injection system on your well, then you don't have any chlorine.

Russ

[Buckeye Hydro]

Originally Posted by jjoos99

I recently burnt through a di resin refill in just 60 gallons of water. My well water is at 460 with 30 coming out of the ro. comes out to be about 93%. I bought this unit used a good year or so ago so I would think I should try a new membrane. Cant keep the di changed fast enough the way it is going. I have a booster pump but it is running about 50 psi.
Jeff

Something is wrong if the pumped pressure is only 50 psi.

Russ

[Buckeye Hydro]

Originally Posted by NotYoNano

.5 micron sediment and carbon from marinedepot(spectrapure brand), buy 50gpd ro membrane for less waste water and using less di resin over time, buy 100gpd ro membrane for more waste but more output and having to replace di resin more often(high silicate absorption membranes available too), get some silica resin for 1 canister(i use filterguys), then an inline tds meter(if dual;first goes after ro membrane) and then 2 canisters of di resin.(silicates will slip through di resin, thus you want a separate canister of silica resin before the di) You'll then just need a few plugs and hose. You'll spend as much as the starter unit's from pretty much any vendor, but you will get better quality water vs resources ratios.

(above is a pre-typed blurb, .5 microns all the way though )
Since adding a 2nd .5 micron carbon block, I find my tds from ro is now 3 instead of 13-15. So it's definitely welcome to extend the life of the di chambers.

Yeow. There seems to be a number of mis-conceptions here.

The AMOUNT of waste water relative to purified water shouldn't change depending on the capacity of your RO membrane. The speed at which it is produced will change, but not the volume.

Adding a second carbon block won't reduce the TDS of your RO water.

Russ

[jjoos99]

Originally Posted by Buckeye Hydro

Something is wrong if the pumped pressure is only 50 psi.

Russ

I changed my pleated prefilter today and my pump pressure it at 70psi. Do I need more pressure then that? My pump is a fluxtek LF33L-50. I have 3 stages of filters before the ro membrane. I have well water alittle heavy in iron and use a cheapo pleated filter to catch the iron. What should I order for the following 2 stages being well water? I am assuming the 5 micron carbon filter mentioned would be in the final filter before membrane?
thanks
Jeff

[shifty51008]

I would go with a 1 micron sediment filter and the 5 micron carbon block.

Now that you have 70psi what is your rejection rate at now?

Another reason if your burning through di so fast could be you have high c02 in your water which will burn through di fast also. To fix that you will have to degass the water before it goes into the di.