TDS 35 RO or not to RO?

[guihan]

I tested my tap water and the TDS is 35 and the Nitrate is 0. I'm thinking about running my 6 stage spectrapure RO/DI without the RO membrane to save on water (no waste water). FYI stage one .5 micron sediment filter, stage two .2 micron sediment filter, stage three .5 Carbon block filter, stage four RO membrane (to be bypassed), stage five DI filter (chloramine), stage six DI filter (SilicaBuster). Would this be a bad idea? Is there anything I'm not considering. Thanks.

 

[zepplock]

35 is very good. I have ~500 and it sucks.
Just make sure no chlor-anything goes through.

 

[xinumaster]

That's a good plan. If my TDS is 35ppm I would do the same thing you have in mind.

 

[sfsuphysics]

With 35 ppm I'd totally ditch my RO part as well.

I don't work for spectrapure or any of those other companies that sell overly priced filters , so I'm not an "expert" in the field.

HOWEVER I think you're might get clogging issues with that setup.

To give you an idea, a human red blood cell is around 7 microns in diameter. So going with a 0.5 micron then a 0.2 micron sediment is IMO way overkill. I would happily go with a 5 micron and then 1 micron if I was really picky.

Also I'd work more to your carbon handling the chloramines, maybe squeeze another one in there? The issue is that you'll be shooting water through the system at a much quicker rate without the membrane, so contact time is crucial, just do some research on various ones, the ones I use work as long as the flow rate is 1GPM or less, which isn't a problem at all with the membrane (that's 1440 GPD! ), however you'll be pushing quite a bit more than I do without a membrane.

 

[guihan]

With 35 ppm I'd totally ditch my RO part as well.

I don't work for spectrapure or any of those other companies that sell overly priced filters , so I'm not an "expert" in the field.

HOWEVER I think you're might get clogging issues with that setup.

To give you an idea, a human red blood cell is around 7 microns in diameter. So going with a 0.5 micron then a 0.2 micron sediment is IMO way overkill. I would happily go with a 5 micron and then 1 micron if I was really picky.

Also I'd work more to your carbon handling the chloramines, maybe squeeze another one in there? The issue is that you'll be shooting water through the system at a much quicker rate without the membrane, so contact time is crucial, just do some research on various ones, the ones I use work as long as the flow rate is 1GPM or less, which isn't a problem at all with the membrane (that's 1440 GPD! ), however you'll be pushing quite a bit more than I do without a membrane.

The water here in Hayward is low in TDS, but very high in sediments. I was using the RO/DI unit as a five stage before with only a .5 micron sediment filter before the carbon block, but the carbon block got clogged after only 600-700 gallons. I then switched to a .2 micron filter and the carbon block is not getting clogged, but sediment filter is clogged after only 400-500 gallons. I was told that it would be best to run an additional sediment filter (1 or .5 micron) before the .2 micron sediment filter to reduce clogging. If I reduce the flow rate down to what it would be if the RO membrane was still in line, would this make the carbon block just as affective as before? Also, there is a couple of DI filter I can get, one that filters silica, nitrate, phosphate, and heavy metals or one that filters chloramines. Any suggestions? Thanks.