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Sad to say I don't. I looked into this once before and the general consensus in the reefing community is that you are further ahead to buy a commercial unit (cheaper ones go for $100 - $150).

To purchase an RO membrain, the filters themselves, and all the plumbing it would require to build one, you are probably gonna save money buying a one. And even if you did buy all this and put it all together, there is no guarantee that the system will work properly (not leak or let water bypass the filters).

What do you need it for anyway? I have used RO before when I had a reef tank but for FW I have always just used treated tap.
 

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What do you need it for anyway? I have used RO before when I had a reef tank but for FW I have always just used treated tap.
Sometimes it is easier to use reconstituted RO than tap water. My tap water ranges in hardness from very soft to very hard, and my angels seem to do much better in soft water, so for me, I'd rather know for sure that I'm putting in soft water than have to test it every time. For my cichlid tank, though, I'm just gonna be using treated tap water because they won't really care!
 

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Discussion Starter · #5 ·
Sad to say I don't. I looked into this once before and the general consensus in the reefing community is that you are further ahead to buy a commercial unit (cheaper ones go for $100 - $150).

To purchase an RO membrain, the filters themselves, and all the plumbing it would require to build one, you are probably gonna save money buying a one. And even if you did buy all this and put it all together, there is no guarantee that the system will work properly (not leak or let water bypass the filters).

What do you need it for anyway? I have used RO before when I had a reef tank but for FW I have always just used treated tap.
For years we have always had soft water out of the tap an in the past couple of weeks its turned to hard water...I didn't even know this is possible. Im just looking for a cheap way to create soft water for my neon tetras, I have read about peat moss and not too sure about the appearance of the tannins it will release.
 

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For years we have always had soft water out of the tap an in the past couple of weeks its turned to hard water...I didn't even know this is possible. Im just looking for a cheap way to create soft water for my neon tetras, I have read about peat moss and not too sure about the appearance of the tannins it will release.
Give it time. it is seasonal.
 

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SCAPEr
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sorry if I hijacked this thread... but I have read in order to make RO water, there must be "waste" water from the filteration right? but dont those "wasted" water cost money coming from the ground? Is there anyway to make RO water without "wasting" any water?

well I'm somewhat conservative, I don't like waste anything... right now I'm planning to buy RO from lfs 49c per gallon.
 

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Nope, RO always wastes the majority of the water. Although you could use it to water a garden or something.

Distillation doesn't waste any water, but uses a lot of electricity.

If the LFS makes and sells RO water, there's still wastewater going down the drain; just their drain instead of yours.
 

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Is it the money or the wasted water that worries you?

You'll have wasted water regardless of your RO water source. In other words if you buy it from the LFS you just wont see the waste but it's still there. lol

It's possible to purify without an RO.
You can use only the DI resins but they will be exhausted rather fast. There's also a system on the market called Kold Sterile. It produces no waste but the product water is nowhere near the same as simple RO. The Kold Sterile leaves most of the minerals like Mg and Ca along with most components that make up alkalinity. It's really targeted for drinking water use and the hobby has never used it much.
 

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The only way to reduce 'waste water' is to run a dual membrane unit. The basic RO unit will waste about 4g of water for each 1g of RO it produces, a dual membrane unit will produce about 1-1.5g of waste water for each 1g of RO water. Thiss is hte only method of wasting less.

Craig
 

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The only way to reduce 'waste water' is to run a dual membrane unit. The basic RO unit will waste about 4g of water for each 1g of RO it produces, a dual membrane unit will produce about 1-1.5g of waste water for each 1g of RO water. Thiss is hte only method of wasting less.

Craig
We get this question a lot - I think we need to add this to our FAQ list: http://buckeyefieldsupply.com/FAQ.asp

Be careful with thinking you can save water by adding a second membrane.

First - remember that what folks call "waste water" really would be better thought of as "flush water" in that this water serves the important purpose of internally flushing the surface of the semipermeable membrane to keep the membrane from fouling/scaling.

When you configure a system with two membranes in series (the waste from the first membrane going to the "in" port on the second membrane), for this discussion let's say it's two 75 gpd membranes, the system behaves like you have a single long (75 gpd x 2) 150 gpd membrane.

Now - if you use a proper flow restrictor, that is, one for a 150 gpd membrane, you'll have about a 4:1 waste to product ratio. Sounds familiar, right?

If however you don't change the flow restrictor - meaning you keep using the same restrictor you were using when you just had one 75 gpd membrane, then you'll see a waste to product ratio much lower than 4:1. But remember that the recommendation for a ~4:1 ratio comes from the membrane manufacturer. They are telling you that you need about a 4:1 ratio to keep the membrane flushed and keep the membrane from fouling or building up scale. Run the system with a lower ratio and you will foul/scale the membrane(s) quicker than would have otherwise been the case.

Instead of adding a second membrane to lower that ratio, you could have just changed out your flow restrictor ($4) instead. A much less expensive approach to get you to the same endpoint in terms of saving on waste water.

Now, to confuse things just a bit. Filmtec specs call for the 4 to 1 ratio on the basis of assumptions about the water that will be supplied to the membrane. If you have very soft water you MAY be able to get a decent service life from the membrane running at a ratio lower than 4 to 1 (e.g., 3 to 1). Remember that the waste water from the first membrane is about 25% harder than your tap water.

Bottom line: If what you are after is reduced waste water, experiment with a different flow restrictor for $4 instead of messing around with a second membrane plumbed in series.

As a side note, you can also lower the ratio by increasing the pressure delivered to the membrane (with a booster pump), because flow restrictors are sized assuming you are providing factory spec conditions (50 psi and 77 degrees for Filmtec membranes). Increase the pressure and you'll drive more water through the membrane and viola - less waste water. But as I mentioned above, if you do this (just like over-restricting a membrane) - the lower the waste to product ratio, the shorter the lifespan on the membrane.

Makes sense?

Russ
 

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SCAPEr
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Is it the money or the wasted water that worries you?

You'll have wasted water regardless of your RO water source. In other words if you buy it from the LFS you just wont see the waste but it's still there. lol

It's possible to purify without an RO.
You can use only the DI resins but they will be exhausted rather fast. There's also a system on the market called Kold Sterile. It produces no waste but the product water is nowhere near the same as simple RO. The Kold Sterile leaves most of the minerals like Mg and Ca along with most components that make up alkalinity. It's really targeted for drinking water use and the hobby has never used it much.

both worries me lol. maybe just maybe I might just get the system if I get tired going back and forth buying RO from lfs.
 

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Water cant be 'wasted' unless your talking about $. Which I dont think you are. Water doesnt magically dissapear from earth after being flushed. Its a non-issue.
 

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SCAPEr
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Water cant be 'wasted' unless your talking about $. Which I dont think you are. Water doesnt magically dissapear from earth after being flushed. Its a non-issue.
yeah.. but I'm just those paranoid kid that watched national geographic channel and now I'm moved by how earth will no longer have fresh clean water so don't waste it lol.
 

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Save your flush or waste water and pour it onto the ground so it eventually ends up back in the aquifer. If your on a municipal system, the waste water is diluting the sewage water and helping the treatment plant out. Again, no water "waste".
 

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We get this question a lot - I think we need to add this to our FAQ list: http://buckeyefieldsupply.com/FAQ.asp

Be careful with thinking you can save water by adding a second membrane.

First - remember that what folks call "waste water" really would be better thought of as "flush water" in that this water serves the important purpose of internally flushing the surface of the semipermeable membrane to keep the membrane from fouling/scaling.

When you configure a system with two membranes in series (the waste from the first membrane going to the "in" port on the second membrane), for this discussion let's say it's two 75 gpd membranes, the system behaves like you have a single long (75 gpd x 2) 150 gpd membrane.

Now - if you use a proper flow restrictor, that is, one for a 150 gpd membrane, you'll have about a 4:1 waste to product ratio. Sounds familiar, right?

If however you don't change the flow restrictor - meaning you keep using the same restrictor you were using when you just had one 75 gpd membrane, then you'll see a waste to product ratio much lower than 4:1. But remember that the recommendation for a ~4:1 ratio comes from the membrane manufacturer. They are telling you that you need about a 4:1 ratio to keep the membrane flushed and keep the membrane from fouling or building up scale. Run the system with a lower ratio and you will foul/scale the membrane(s) quicker than would have otherwise been the case.

Instead of adding a second membrane to lower that ratio, you could have just changed out your flow restrictor ($4) instead. A much less expensive approach to get you to the same endpoint in terms of saving on waste water.

Now, to confuse things just a bit. Filmtec specs call for the 4 to 1 ratio on the basis of assumptions about the water that will be supplied to the membrane. If you have very soft water you MAY be able to get a decent service life from the membrane running at a ratio lower than 4 to 1 (e.g., 3 to 1). Remember that the waste water from the first membrane is about 25% harder than your tap water.

Bottom line: If what you are after is reduced waste water, experiment with a different flow restrictor for $4 instead of messing around with a second membrane plumbed in series.

As a side note, you can also lower the ratio by increasing the pressure delivered to the membrane (with a booster pump), because flow restrictors are sized assuming you are providing factory spec conditions (50 psi and 77 degrees for Filmtec membranes). Increase the pressure and you'll drive more water through the membrane and viola - less waste water. But as I mentioned above, if you do this (just like over-restricting a membrane) - the lower the waste to product ratio, the shorter the lifespan on the membrane.

Makes sense?

Russ
Sorry its late and my brain may just not be working at 100%. Are you sating that if I change the flow restrictor (I have a 75gpd membrane and a 75gpd restrictor) to a 150gpd restrictor I will get a more efficient use of my system but at the expense of membrane life?
 

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Water cant be 'wasted' unless your talking about $. Which I dont think you are. Water doesnt magically dissapear from earth after being flushed. Its a non-issue.
Lol. I live in mn and trust me we have the water. If it goes down the drain or in the ground well that's mother nature doing what we are talking about. Filtering the water lol. Imo anyways.
 

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We get this question a lot - I think we need to add this to our FAQ list: http://buckeyefieldsupply.com/FAQ.asp

Be careful with thinking you can save water by adding a second membrane.

First - remember that what folks call "waste water" really would be better thought of as "flush water" in that this water serves the important purpose of internally flushing the surface of the semipermeable membrane to keep the membrane from fouling/scaling.

When you configure a system with two membranes in series (the waste from the first membrane going to the "in" port on the second membrane), for this discussion let's say it's two 75 gpd membranes, the system behaves like you have a single long (75 gpd x 2) 150 gpd membrane.

Now - if you use a proper flow restrictor, that is, one for a 150 gpd membrane, you'll have about a 4:1 waste to product ratio. Sounds familiar, right?

If however you don't change the flow restrictor - meaning you keep using the same restrictor you were using when you just had one 75 gpd membrane, then you'll see a waste to product ratio much lower than 4:1. But remember that the recommendation for a ~4:1 ratio comes from the membrane manufacturer. They are telling you that you need about a 4:1 ratio to keep the membrane flushed and keep the membrane from fouling or building up scale. Run the system with a lower ratio and you will foul/scale the membrane(s) quicker than would have otherwise been the case.

Instead of adding a second membrane to lower that ratio, you could have just changed out your flow restrictor ($4) instead. A much less expensive approach to get you to the same endpoint in terms of saving on waste water.

Now, to confuse things just a bit. Filmtec specs call for the 4 to 1 ratio on the basis of assumptions about the water that will be supplied to the membrane. If you have very soft water you MAY be able to get a decent service life from the membrane running at a ratio lower than 4 to 1 (e.g., 3 to 1). Remember that the waste water from the first membrane is about 25% harder than your tap water.

Bottom line: If what you are after is reduced waste water, experiment with a different flow restrictor for $4 instead of messing around with a second membrane plumbed in series.

As a side note, you can also lower the ratio by increasing the pressure delivered to the membrane (with a booster pump), because flow restrictors are sized assuming you are providing factory spec conditions (50 psi and 77 degrees for Filmtec membranes). Increase the pressure and you'll drive more water through the membrane and viola - less waste water. But as I mentioned above, if you do this (just like over-restricting a membrane) - the lower the waste to product ratio, the shorter the lifespan on the membrane.

Makes sense?

Russ
Really good info.
I was going to get another membrane and membrane housing to add on my current RO unit, now I know what to do, thanks
 
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