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stuart0413
05/25/2008, 08:13 PM
i just bought a tds meter and tested my ro water. it read 38 ppm. i thought that was a bit high and bought new filters and membrane. when i retested, the level says 40 and my outflow is super slow. the membrane was about 5 yrs old and i change filters every 4 mos or so. what is an acceptable tds level? i tested the discharge water and it read 173.

usmcsgt
05/25/2008, 08:48 PM
Are you running an ro unit or a ro/di?

xdfireguy
05/25/2008, 08:52 PM
With RO/DI I am comfortable with a 0-3 ppm reading. I am getting 140 coming in.

useskaforevil
05/25/2008, 08:53 PM
i've got 10ppm out of mine, 200 some comming in. i figure, till better than tap water, which some people use, havent had any problems

usmcsgt
05/25/2008, 08:57 PM
But the question is, is it just an ro filter or is it ro/di.. that can make alot of difference.

stuart0413
05/25/2008, 09:06 PM
it is r.o. only. is it possible/difficult to add a d.i.? seachem pinnacle + 100 gpd. water coming in is 214. says it has 96% rejection, but from my readings it seems to be only 82%. i probably should have spent a little more. i don't have any chronic algae issues, just a little bubble algae in a certain spot that is shaded by a large vertical tonga branch. good water movement.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=270187689032

ReefEnabler
05/25/2008, 09:11 PM
are you sure that your previous membrane was a 100gpd???

it could be that you are using the wrong flow restrictor. you should have a product to waste ratio of roughly 4 to 1 depending on a few things.

What is the cold water temp?? what is the water pressure?

place a measuring cup and measure both the pure water output and waste water for the same time period and post what the ratio currently is.

If the ratio is off then you most likely have the wrong flow restrictor on your waste outlet for that particular membrane combined with your local variables.

xdfireguy
05/25/2008, 09:16 PM
Good point, you cannot just put any membrane in any filter housing and expect it to function properly without the correct flow restrictor. The two have to match.

stuart0413
05/25/2008, 09:20 PM
yes, it came with the unit. i am sure the ratio is much higher than that. right now it is only producing about 3 gallons per hour of good water. but i have not done anything to it as far as changing the restriction flow. this membrane just does not seem compatible. pressure is 62, water temp very cold. we are in a rural area and have very hard water with lots of minerals.

ReefEnabler
05/25/2008, 10:49 PM
your pressure seems high enough.

if your 3 gph is accurate, then thats 72 gallons per day. This is not actually that low for a 100gpd, but for your water pressure it should be higher IMO unless your water is near freezing..... or the flow restrictor is wrong.

get a capillary flow restrictor from spectrapure. they are a long thin tube that you trim to a certain length based on the directions in the manual. they give you an equation with expected GPD, pressure and temperature and then you figure out how long to cut it.


Also worth asking, do you flush the membrane before using it? Its suggested that when using a membrane for the first time, or after a long period of inactivity that you flush it by allowing full waste-drainage for several minutes.

I'm still setting up my build so I only use the RODI unit occasionally. if I dont flush it, the RO membrane is putting out ~10-20ppm. after flushing its 0ppm. My tap water is ~130ppm so the spectrapure 98% guarentee is outdoing itself there.

schigara
05/25/2008, 11:03 PM
Wow! My tap is about 65ppm and after my sediment, carbon and 75gpd Filmtec membrane, I get about 3ppm TDS. The first DI reads 0ppm TDS as well as the 2nd DI cartridge.

usmcsgt
05/26/2008, 10:15 AM
adding a Di is not that hard

Bambalam
05/26/2008, 11:13 AM
The tapwater here is 471 ppm. Thankfully there's a couple grocery stores with water machines who's water reads between 3 and 17 ppm.

ReefEnabler
05/26/2008, 12:03 PM
wow, so for you is it actually cheaper to continue to buy the grocery store RO water rather than invest in your own filters?
I imagine you'd burn through RO memrbrane and DI resins like no tomorrow with tap water like that.

Bambalam
05/26/2008, 12:08 PM
<a href=showthread.php?s=&postid=12616590#post12616590 target=_blank>Originally posted</a> by RyanBrucks
wow, so for you is it actually cheaper to continue to buy the grocery store RO water rather than invest in your own filters?
I imagine you'd burn through RO memrbrane and DI resins like no tomorrow with tap water like that.

That is exactly my thinking. The grocery store water is 35 cents a gallon, and hey - ya gotta get groceries all the time anyway.

Been_There8
05/26/2008, 12:16 PM
Lol, am i the only person here with tap water at 0? Kitchen, restroom, tiolet, bath, tested all, was really amazed. Still use R/O though, i buy from my LFS, stupid iron killed 3 of my shrimps,

ReefEnabler
05/26/2008, 12:18 PM
35 cents a gallon eh... not bad unless you're about to fill up 400 gallons like I am about to do :D

been there,
where are you located?

I have never heard of tap water with 0ppm.... what are you testing with??

Ryan

usmcsgt
05/26/2008, 07:16 PM
<a href=showthread.php?s=&postid=12616284#post12616284 target=_blank>Originally posted</a> by Bambalam
The tapwater here is 471 ppm. Thankfully there's a couple grocery stores with water machines who's water reads between 3 and 17 ppm.

When I was in NC I had tap water that was around that and my RO/DI worked great on it and it didnt burn through filters.

auntdeb
05/27/2008, 01:36 AM
You guys are all doing well. Here our water is 580+ from the tap. But thanks to the RO/DI, my water is 000's! The under sink RO is reading 35 or so and would like to get that down in the teens.