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.
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.
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
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.
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...
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.
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
Last edited by Av8tor1; 05-25-2011 at 09:25 AM.
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. ^.^
like drilling carb jets if youve ever raced any