Is having an RO filter really worth it?

[cee]

4:1 is a more typical ratio of wastewater to RO water. I seem to recall if your ratio is lower you will not filter the water as effectively with the membrane and will exhaust the DI resin beads more quickly.

Dave

 

[Engloid]

I think that means the restricter thing is rated up to 600gph, not that you actually have high enough water pressure to get 600gph through there.

So what else could be wrong that I'm not getting near the RO water I should? Water pressure here at the house will send the poly tube into a frenzy if I open it up, but through the filter, I get just enough that it's not breaking into separated droplets. I get great pressure through all of the three canisters, but only a little bit out both sides of the RO membrane.


The manufacturer actually says that the valve on the waste line shouldn't even be there and it should flow freely...but when I open it up I get MUCH more than 2.5x the RO flow, and the RO flow drops even more.

 

[cee]

So what else could be wrong that I'm not getting near the RO water I should? Water pressure here at the house will send the poly tube into a frenzy if I open it up, but through the filter, I get just enough that it's not breaking into separated droplets. I get great pressure through all of the three canisters, but only a little bit out both sides of the RO membrane.


The manufacturer actually says that the valve on the waste line shouldn't even be there and it should flow freely...but when I open it up I get MUCH more than 2.5x the RO flow, and the RO flow drops even more.

Don't restrict the wastewater line with a valve, that makes the membrane inefficient. Sometimes you have to trim the flow restrictor to get the correct ratio. I don't think you've stated what the rating is on your membrane; that will definately effect the RODI output.

 

[Engloid]

Don't restrict the wastewater line with a valve, that makes the membrane inefficient. Sometimes you have to trim the flow restrictor to get the correct ratio. I don't think you've stated what the rating is on your membrane; that will definately effect the RODI output.

the flow restrictor is a cylinder shaped thing on this unit. It has the tube fittings on both ends. I don't think it can be adjusted or trimmed. When you say a valve could reduce efficiency...but what do you mean? I understand that if I close it, I will basically fill the membrane with impurities since it has nowhere to go. I also know that the life of the membrane will be reduced if I restrict the waste too much. I'm just trying to get to the 2.5:1 ratio that the manufacturer said I'd get. Is that not something I should worry with?

Good point on the membrane rating. Not one I hadn't thought about...but possibly I didn't think enough about it. :lol: The membrane is rated at 100gpd, which would mean 2.4gph. hmmmmm I will have to time it next time and see how long it takes to get some water. I may be close to it and was just expecting more, but not paying attention to the time thinking I was nowhere near what it should be.

thanks for the help!

 

[cee]

the flow restrictor is a cylinder shaped thing on this unit. It has the tube fittings on both ends. I don't think it can be adjusted or trimmed. When you say a valve could reduce efficiency...but what do you mean? I understand that if I close it, I will basically fill the membrane with impurities since it has nowhere to go. I also know that the life of the membrane will be reduced if I restrict the waste too much. I'm just trying to get to the 2.5:1 ratio that the manufacturer said I'd get. Is that not something I should worry with?

Good point on the membrane rating. Not one I hadn't thought about...but possibly I didn't think enough about it. :lol: The membrane is rated at 100gpd, which would mean 2.4gph. hmmmmm I will have to time it next time and see how long it takes to get some water. I may be close to it and was just expecting more, but not paying attention to the time thinking I was nowhere near what it should be.

thanks for the help!

I think the 2.5:1 is optimistic and will shorten the life of the membrane and/or resin beads. 4:1 is what SpectraPure claims is ideal. If I recall correctly, the most efficient RO membranes are the 75 gpd units. Somewhere there is a study that was done that examined the efficiency of differently rated membranes vs. the membrane's rating and I believe the Filmtec 75 gpd came out on top. It's been years since I researched that one and my memory isn't what it used to be...

Dave

 

[hondo3]

I hope so! I just bought one!

 

[Wildman]

When I was researching I was told the 100 gpd was a little less efficient to gain the extra 25gpd output. It just depends on where you're priorities are, more efficient or more flow.