RO/DI water - TDS meter = 6

[Playdope]

Hey all,

Ever since I started running my RO/DI from www.filterdirect.com, I noticed my water was reading 006 on the TDS meter. I read somewhere that RO/DI should be 0-2 on the TDS meter, so I am wondering if I should replace something, or whats going on?! Anyone have thoughts?

Jon

 

[ufans]

I assume you are talking ppm

If you have RO+DI then it really should be 0ppm. What did the source water start at?

Make sure you are not sampling the first stream of water out of the unit or the water that sits out for a while. My RO/DI water reads 0ppt (yes ppt).

But, still.. 6ppm is still quite pure. You might want to run some PO4 and other tests on the water to figure out what is in it.

 

[Anonymous]

Keep in mind that even a small amount of salt will raise the TDS on RO/DI a lot. In order to measure the reading right, you need to flush the RO/DI for a while, and make sure the meter's probe is perfectly clean. CO2 in the air can give a couple PPM to RO/DI, for example.

 

[Playdope]

I have let the unit run for about 5-10 min and it still reads 006 ppm after I test it with TDS meter. Maybe the filters aren't top notch?

Please help... I bought ro/di for a reason, and I really dont know what to do.

Jon

 

[Anonymous]

6ppm is not that bad, slightly better than straight RO.

Test the TDS of RO (no DI), and see how well your RO is working. Then we can play troubleshooting.

 

[Playdope]

How do I do that? Not sure how to do that individually.

Jon

 

[Anonymous]

see the twin thread about filter size:
http://reefs.org/phpBB2/viewtopic.php?p=531857

Anyway, put the probe of your TDS meter right after the RO, but before the DI, and do the reading there. Or collect the RO (not DI'ed yet) water in a clean cup, and dip the probe in it.

 

[Anonymous]

How do I do that? Not sure how to do that individually.

Jon

There should be a little hose connecting the RO unit to the DI part, you can disconnect that and test the water before it goes into the DI unit.

 

[Anonymous]

Whats you staring TDS?

In my case my staring TDS is 350ppm. RO usually custs that by 90%.
My water after my RO is 35ppm. A
After my first DI it is 4
After my second DI it is 0.
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[Ben1]

I had a TDS of about 4 after my DI unit on my kent marine RO?DI unit. I added a second DI from buckeyefieldsupply.com and have had a 0 reading since.

 

[Playdope]

OK all,
I got the reading just before DI, and to my suprise I got a reading of 3 ppm, so I figured I would test it again after DI ... and low and behold the same 3 ppm.

A few concerns/thoughts:

1. When I took the reading before and got 6 ppm, it was from a bucket (has only been used once to store SW - then rinsed with tap). So I'm guessing thats where the extra 3 ppm came from. Is this bad, or totally notmal that storage containers will add a few extra ppm?

2. Whats up with this.. I get the same reading before and after DI!? Why did I even bother getting RO/DI from this company?!

Thanks,
Jon

 

[SCIronMike]

I installed my Filter Direct RO/DI unit today. My TDS before filtration was ~570 ppm. The water that I have been buying from my LFS up to this point (just RO water, no DI) was 14 ppm. The RO/DI water coming from my new unit is 0 ppm. Yowza!

 

[Playdope]

Palos Verdes ey? I went to Marymount College.

As for the Filter Direct unit, which model do you have? Does your DI have a part number?

Jon

 

[SCIronMike]

I got the RO6100 + DI unit that they sell online. All their units use the same filters I think. You sure you installed it properly and let the first 5 gallons or so run off?

 

[SCIronMike]

Ok..... having fun with my TDS meter.

Tap water = ~570 ppm
LFS RO water = 14 ppm
Filter Direct RO water = 20 ppm
Filter Direct RO/DI water = 0 ppm
Arrowhead drinking water = 270 ppm

Overall this Filter Direct RO/DI unit is pretty sweet for the price.

 

[Playdope]

Very strange that your Filter Direct unit with just RO is putting out water with 20 ppm, and mine before DI is putting out 3 ppm?!? Very very weird. How are you feeding your unit? You wouldn't by chance have yours connected to a faucet adapter?

Also, are you using one of those handheld beige TDS meters from filter direct?

Jon

 

[Anonymous]

RO filters will only reduce the PPM's by ~90% so getting 20ppm after the RO is great IMHO.
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[Playdope]

Problem is...
I'm getting 3 ppm after RO... but when I check after adding DI to that....
I'm still getting 3 ppm. I'm gonna call the company today. Maybe it's a bad DI filter.

Jon

 

[Playdope]

Problem is...
I'm getting 3 ppm after RO... but when I check after adding DI to that....
I'm still getting 3 ppm. I'm gonna call the company today. Maybe it's a bad DI filter.

Jon

 

[Anonymous]

>>...Keep in mind that even a small amount of salt will raise the TDS on RO/DI a lot.
>...totally notmal that storage containers will add a few extra ppm?

Depends on your source water, 3ppm after RO maybe normal for the filter. IronMike told you how bad his water is (>500PPM), but I don't know if your water is any worse than his.... what is your tap TDS?

>...I'm still getting 3 ppm. I'm gonna call the company today. Maybe it's a bad DI filter.

Before calling them up, you may want to check your TDS meter making sure it is not test eqipement issue, or "user error." It may save you from some minor embrassment (done that myself... ops).