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Yet another RO unit thread

  • #101
Alrighty, we'll see what TDS I get without the DI.
 
  • #102
did you verify your tds meter with some distilled water?
 
  • #103
No, not yet. Still in my PJs, LOL.

I'm not sure how to give feedback to this seller... Normally, I'd give negative feedback, but in this case it's between neutral or positive. Yes, there were broken parts. That sometimes happens in shipping, it's inevitable. Granted, their packing was far from the best, but still. The reason I'm conflicted is because I've now contacted them twice, on two different days, regarding two different issues, and both times they've had replacement parts on the way with priority postage the very same day. They're doing their absolute best to fix the issues. They never even questioned me about the broken parts, either. The DI canister lid, for example, could well have been broken by me over-tightening the fitting that screws into it (I didn't, I was very careful about it), but they didn't even mention it. I told them the part was broken and they said "must have crack during shipping. Will ship out today." You really can't beat that kind of post-sale support...
 
  • #104
times like those I have simply left no feedback... but that is a call you got to make.

they may have never seen it (drop shipped by a 3rd party), may have been some flunky doing the shipping that day, or who knows... do-do does happen to the best of us
 
  • #105
Yeah, I don't know. We'll see.

Now, if I measure the TDS right out of the membrane, I'm reading 4ppm. If I measure at the spigot, with the tank closed, about 19ppm. If I measure at the spigot with the tank open, about 12ppm. That last bit is sort of strange, being I emptied the tank of all of the water from last night (the water which had been through the DI stage) and let it refill with water from today, no DI stage. So the water from the tank SHOULD be the same TDS as the water that comes right from the unit to the spigot. I don't know. It seems my brine ratio has gone up (the permeate output is much slower) so I'm going to go remeasure that and I'll remeasure water right before and after the membrane again.

We'll get this hammered out, LOL.

---------- Post added at 06:50 PM ---------- Previous post was at 06:41 PM ----------

Before membrane: 63ppm.
After membrane: 7ppm.

Still at about a 2.2:1 ratio. Seems that everything is just moving slower than yesterday, the pump even seems to be cycling slower. Maybe I'm imagining it. I need to get to Lowes and get that gauge...

---------- Post added at 06:53 PM ---------- Previous post was at 06:50 PM ----------

Mmmm, might've just pinpointed a possible suspect... directly out of the carbon post filter is 29ppm.

EDIT: Can I try having the water go straight from the permeate out of the PP to the tank? Bypassing the carbon post filter and DI stages completely?
 
  • #106
other then the variance in TDS, the rejection ratio is sounding much better

not sure why your tds would be doing what its doing, logic dictates an issue with the measurements.... or we could still have some trash purging from the system...

Sometimes I tell my students it is a case of "FM"
(freaking magic LOL)

Ideally, I would hope to see your rejection ratio hit 90% or better and a brine rate closer to 4:1 (which may happen with a little use)

The carbon post filter is producing "fines", it should clear up and is of no concern... this is characteristic of GAC units,

bypass for a test if you wish, its main purpose is to remove any VOC that may gassed off by the tank bladder
 
  • #107
Yeah, 89% is pretty close (unless I'm totally calculating that wrong).

Did you catch that add-on in the post above? About the carbon post filter?
 
  • #108
yep, and edited reply :)
 
  • #109
Haha, excellent. By bypassing the post filter, will it leave anything of any harmful nature to plants? I do not intend to use it as drinking water, just for the plants. Also, are those "fines" of any danger to the plants? Or is it just carbon? I can't imagine carbon dust would be dangerous to the plants, but then, I can't imagine it would conduct electricity and register on a TDS meter (isn't that how they work?).
 
  • #110
shouldnt be an issue either way mate....

and omg RO/DI makes the best sun tea and coffee

fresh ground Kona beans and RO/DI :)
 
  • #111
Alright, I'll try that then. I'll empty out the tank, and route the permeate directly to the tank, no post filtering. See how that goes.
 
  • #112
Some interesting news.

1) TDS reading on the store-bought distilled water is 0ppm.
2) Water pressure at the cold water inlet (with system running) is ~80psi.
3) I bought what I thought was a ball valve (it sure looks like it to me...) except that when a little pressure builds up (and I mean a little, maybe one second's worth of the system running) the little lever part on it used to closed and open the valve pops up and water comes pouring out of it. WTH? So now my system is essentially useless until tomorrow when I can get a real ball valve since I essentially have an open hose on the system. I suppose I could cut a new length of hose to get rid of that... probably will... Ugh.
 
  • #113
80?..... wow, ummm well 2.2:1 may be perfectly normal at that pressure (higher pressure/lower brine rate)... LOL, its a good thing... 90 is max for most membranes
(I think, this is very uncommon.... usually its not enough pressure, not too much)
That would also explain why your Permeate pump cycles faster then mine

There is one issue I know of that occurs sometimes with excessive pressure. On the exterior of the membrane is a seal that is taped the the membrane housing. It seals the exterior circumference of the membrane to the interior circumference of the membrane housing. It has been know to fail under excessive pressures (very rare, but something to remember if you ever have issues with a radical drop in performance.

umm 80psi huh.... cool LOL

Reaper, put that thing together and run it for a couple weeks and then restest, let things stablize mate... ;-)

curious, do you ever have issues with the ballc0ck valve in your toliet(s)?.... 80 is pretty unusual
 
  • #114
I've not noticed any issues with the toilets, no. But then, we've only lived here since December, maybe there will be some surprises down the road, haha. It's strange that the pressure in the kitchen is so high. The pressure in the upstairs shower is pretty horrible, LOL.

I will periodically test TDS to make sure nothing has gone awry (like the tape seal failing in the membrane). Now I'm happy to know I'm getting such a good brine rate due to some normal, explainable thing, not some error in my setting up or some issue with the unit. I certainly will not complain about getting such efficiency from my unit, LOL. I just wish the TDS would go down. I'm at around 14 right now, from the bladder. Meh. And now, since the dH2O gave me a reading of 0ppm, I know it's not the meter. What a pain. Could it be because the high pressure is forcing too much through the membrane too fast? Would a more... restrictive restrictor (LOL) potentially help cut the TDS down?

And, yeah, once I get my replacement cap for the DI canister (assuming I get it before I leave), the system's being left alone, but closely monitored. Right now, it's sitting under the sink, all set up (minus the DI stage), with a full tank of fresh water. Interestingly, when I tested the water from the tank this morning, it was at 8ppm. Now, with the exact same setup, like 14ppm. Will be interesting to see if it's lower again tomorrow morning, even though it'll be the same water that's in there tonight. If so, that would suggest the "fines" from the carbon are settling in the tank.

Thank you so much, Butch, I can't begin to express my gratitude for all your help and guidance.
 
  • #115
well remember the brine rate is there to constantly flush the membrane clean... so a reduction in rate means your membrane may need more occasional manual cleanings....

even with mine at 4:1 I usually do a manual clean before I replace the prefilters... typically for a half hour or so

and it may go up some over time...

On the subject of rejection ratio, the higher pressures should improve it as well.... but with 80 I really dont know, there may be a point of dimishing returns.... the membranes are rated at 50 or 60psig

I would have to go back to the performance charts and see

My gut tells me that its probably an "economy" membrane.... the ratio really should be 95%-ish

But having said that I really wouldnt be too concerned....but when it comes time to replace the membrane I would get a name brand unit.

You are likely to see a small improvement in both areas over the next couple weeks...

Nice work, nice system and a lot of bang for the buck...
 
  • #116
Ahhh, yes, that's true about the membrane getting dirtier faster. I'll have to invest in a bypass when I get back. What's the proper way to use them? Just open it up for half an hour? How often you think would be good to do it with my circumstances? Can you do it too frequently?

In other news, Upon very close inspection last night, three of the ports leading into and out of the prefilter canisters were leaking, albeit very slowly. Took them all off, pulled all the teflon off, put new teflon on, tightened back up... It took like 4 attempts of doing that to get them to stop freakin' leaking. And I think one still is. Argh. Am I just retarded with teflon? Who knows, but at least 2 of them seem to be fixed and the last one is incredibly slow if it is, in fact, still leaking - like, 2 or 3 hours to see a tiny bead of water.
 
  • #117
Im not a big fan of teflon tape for liquid applications.... blue loctite is a great alternative... but you would have to make sure the connection is dry and let it set up.

The difficulty with water leaks may be related to the 80psi

To clean the membrane you simply bypass the flow restrictor... this allows full flow across the membrane, flushing its surface clean.
(ubber high brine rate)

You can buy two tees and a ball valve and make your own clean bypass. Put one tee upstream of the restrictor, one downstream and install the ball valve in this bypass loop.

My combination valve is actually just a ball valve with an orifice drilled through the ball when in the closed position. (which should be really easy to make as well)

as a rule of thumb, flow rate increase is exponential to orifice size, doubling the diameter gives 4x the flow rate through the orifice

If it was mine and I still had 2.2:1 after a month or so, I would consider opening up the restrictor a little.... but that can be tricky and probably not for a frist time user. You gotta take baby steps, if you make it too big there is no going back. Some vendors sell a needle valve type restrictor that s fully adjustable.

Butttttttttt I wouldnt worry.... this is just tweaking for optimal performance and fun to talk about

hmmmm come to think of it, i probably have a small needle valve laying in a junk drawer in my lab.... next time im by campus ill dig around for it
 
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  • #118
Yeahhhh, I'm horrified of cement. I don't even like doing it with PVC and in that case I can just cut out any leaks and replace the section. With this, I'd ruin the canister entirely. If I can't get it to stay leak free (and I bet I can - the other two are fine), I'll probably just set the thing on a plastic tray or something. Like I said, it's a realllyyyyy slow leak, the water would probably evaporate off the tray faster than it can drip, LOL. But we'll see.

And, yeah, I'll probably just make my own bypass, then. Easy enough, and no doubt cheaper.

I won't worry about dealing with restrictor just yet, like you said. If it comes down to it, I might very well be able to open it myself... Putting a bit that's slightly larger than the hole through it shouldn't be too much of an issue, I wouldn't think. What, do you just keep very slowly opening it until you get a rate you're happy with?

And, yet again, I appreciate your generosity. ^.^
 
  • #119
yeppers....

like drilling carb jets if youve ever raced any
 
  • #120
And I'm back from my trip, got the DI stage installed, and am rocking 0ppm. Whee!
 
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