Something off with RO/DI production

[jdavid]

I have the coralife pureflo II, and I just installed new filters on it a couple days ago.

Well I am making water with it and it seems like it may be putting out water too fast, so I decided to test the amount of pure water vs waste water.

Here's what I got:

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In 16 minutes I got what I would say is about 1/2 gallon of pure water. I stopped before the cylindrical part of the container filled so that I could compare the volumes better, but I can figure out exactly how long it takes to make a gallon of pure water later.

My issue is this: I thought that a 50 GPD unit would produce a pure:waste ratio of about 1:3 (yes I did install a 50 GPD membrane so that is not the issue). However my test clearly shows that I am producing over 1/2 the amount of waste water in pure water.

I would think that the issue would be that the RO membrane is not seated properly, however I just installed it and I really think it's in there as far as it can go. I have the unit hooked up to a hose from outside with no booster pump.

Thoughts?

 

[Reefplumber13]

Tagging along

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[jdavid]

Ok so I figured out it's taking me a little less than 1/2 hr to make 1 gallon of pure water.

Which means in an hour I'm making a little over 2 gallons.

Now I know this math is extremely complicated, I had to use a calculator and scratch paper but my calculations are as follows:

24(2)=48

24 being the total number of hours in a day, 2 being about how many gallons (slightly less actually) of water my unit produces in an hour, and 48 being (again, slightly less) than the amount of gallons per day.

That puts my production right in the ballpark of 50 GPD.

So maybe the pure:waste water ratio is not an issue.

 

[acroholic]

Have you checked the TDS of the product water? That would tell you for sure how things are working. I would not worry too much about the wasteroduct water ratio as long as your flow restrictor is correct, etc, and the TDS of the product water is where it should be.

 

[jdavid]

The interesting thing is Dave this unit actually does not have a flow restrictor as far as I can tell.

I do have one on the waste water line of my old unit that says "450" and the direction of flow on it, but that one is for a 150 GPD unit.

I looked all through the manual, it doesn't have a flow restrictor in the parts list or say anything about one or show one in the illustrations.

I've gotta get a dual inline TDS meter. But I need to do a water change before that is actually going to happen because money is sort of tight! Okay it's really tight. I'm stocked up on salt and other stuff and likely to start a new job very soon so that's just one more thing to add to the growing list of things I need!

If anyone reading has one laying around I may have something you'd like to trade for. But tomorrow I'm just going to have to suck it up, hope it's working right with brand new filters and use a little prime for peace of mind :/

 

[sewer urchin]

I looked all through the manual, it doesn't have a flow restrictor

I'm not saying that this is the case but, could the flow restrictor be in of the fittings on the RO housing? I was familiar with the in-line restrictors and I "tinkering" with some of the old fitting and thought that one had clogged up- nope it was a restrictor in the fitting. Talk about some head scratching till I figured it out ;-)

 

[jbdreefs]

You live near me. You can bring a jug of product water to test with a TDS meter.

 

[jdavid]

Yeah, it has to be, because upon further inspection it does mention that in order to flush the membrane, you simply switch the waste line and the product water line.

Still doesn't say it has a flow restrictor, but I just removed the fittings and looked at them and the waste water fitting is different.

My old unit had a flow restrictor that was actually on the waste line and about the size of a roll of pennies.

 

[acroholic]

Did you check the waste line leaving the RO membrane housing? Flow restrictors can look like this:

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Or it sounds like you are familiar with this type, which is what I have on my setup:

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[jdavid]

Yep, I'm was looking for the kind in the second picture, but this unit has the kind in the first picture

 

[acroholic]

JDavid;947142 wrote: Yep, I'm was looking for the kind in the second picture, but this unit has the kind in the first picture

If your RO is a 50 gpd unit and the membrane is a 50 gpd unit, then you should be OK because you would have a 50 gpd flow restrictor.

Your flow restrictor must be matched to your membrane production capacity. So if you change your RO membrane to a 75 gpd one, you need to remove the 50 gpd flow restrictor and replace it with a 75 gpd flow restrictor, etc. Either type restrictor can be used.

 

[jdavid]

It is a 50 GPD unit with all stock parts, and I just put a 50 GPD membrane in.

Before I realized I'm actually making water at the correct rate I thought something was wrong

 

[jennm]

Are you getting more product water than you were before?

If so, there could be a a few reasons - some OK, some, not so much.

Bad reason: If flow restrictor is misplaced, or if RO membrane isn't seated correctly. Checking TDS of product water will tell, that or re-seating the membrane to make sure it's in there right.

It's a bit warmer outside, so the molecules aren't as close together as they are when it's colder - and cold water coming into the house is colder when it's cold out, than when it's warmer out. Warmer water passes through the membrane more quickly... although do NOT put warm/hot water through your unit or it will ruin the membrane.

It could also be that your old membrane was so plugged up with schmutz (yes, that's a technical term LOL) that the new one just has the unit working properly, when it wasn't before.

Just some food for thought

Jenn

 

[jdavid]

JennM;947195 wrote: Are you getting more product water than you were before?

If so, there could be a a few reasons - some OK, some, not so much.

Bad reason: If flow restrictor is misplaced, or if RO membrane isn't seated correctly. Checking TDS of product water will tell, that or re-seating the membrane to make sure it's in there right.

It's a bit warmer outside, so the molecules aren't as close together as they are when it's colder - and cold water coming into the house is colder when it's cold out, than when it's warmer out. Warmer water passes through the membrane more quickly... although do NOT put warm/hot water through your unit or it will ruin the membrane.

It could also be that your old membrane was so plugged up with schmutz (yes, that's a technical term LOL) that the new one just has the unit working properly, when it wasn't before.

Just some food for thought

Jenn

Thanks Jenn I actually did open to check the seating of the membrane and the stem with o-rings (although it can't be seen) must be all the way down in to the canister and the stem on the side that you can see extends just barely past the canister without the cap as the manual says (1/4-1/2")

I am gonna get the TDS meter but with prime I'm kind of not too worried about it. I don't know of any negative effects of using prime all the time and I don't have anything that's really sensitive to phosphates so I'm not too worried about it.

I would like to know though, that the filter is working and then when to change the filters again

 

[redstang]

Late to the party but I have the same unit and same experiences. My water has tested 0 TDS since day one but then my tap is only 40-50 TDS anyway.