interesting TDS reading

[kahnsell]

I just purchased a TDS tester when I got my new RO/DI system off e-bay. I haven't cahnged the filters on my old unit for probably a year, yet that water tests at 2. However, after running 5 gallons of my new RO unit's water, the TDS reads as 78. My tap water is at 199. CAn these readings be correct???

 

[sebae0]

sometimes on a ro/di unit there is some "break in" time and this could be why.

 

[kahnsell]

That's what I thought... I already ran 5 gallons through it. I guess I will continue to run it until they numbers go down.
I just thought it was interesting that my old unit (which was only 3 stages) was cranking out water that was almost perfect on the meter. Perhaps I should keep using my old unit, it's just slow as hell...

 

[wrassie86]

my old ro said it had to run for 24hrs before use.I just bought a ro/di off ---- a few months ago a 6 stage, i've been using it for about 2 months and so far i'm not to happy with it (altho i have not tested the water, i think it would test high TDS).my old unit was a kent HI-S. i think i will be buying a new membrane for the old unit and swaping the ro part out.
What unit did u get? I felt like i got a hell of deal on it,but i also think i got what what paid for.

 

[kahnsell]

Why don't you like yours???
We probably got the same one. Got it for $95ish on e-bay. It's made by WaterGeneral Manufacturing.
I have now ran 30 gallons, and my TDS #'s are coming down...

 

[wrassie86]

YA sounds like we have the same one.
Well the reason i dont like it is silicate.my old unit was a high silicate removal system as was the DI.the one i got from ---- is not high silicate removal.And of course WI water is filled with silicates.
So what i was left with is, diotom blooms and constanly cleaning my glass.were as before i didnot have these problems i was lucky if i cleaned my glass once a month.
So the unit it self is great, now it's just changing out to the Kent HI-S membranes.then it will be a awsome unit.
To bad that membrane cost more than i paid for the whole RO/di unit.
let me know what your tds is after 24hrs.chances are living IL you have better water.but then again we know where our water come from.

 

[golfish]

And some RO membranes are better then others. It wouldn't shock me to see a unit off ---- produce a high TDS. I have a buddy who bought one from ---- 4 months ago. He said it was zero up until last week, now its 150+...
The old saying "you get what you pay for" is something people should take note of.

 

[krustytheclownfish]

"You get what you pay for" applies to a lot of things, but I'm not sure with RO/DI units. I looked around for awhile, read a lot of opinions and reviews, and finally figured it wasn't worth spending hundreds of dollars when I could get a unit cheaper that does what I want it to do...bring my TDS down around 0. Sure you might lose some add-ons like a pressure gauge, clear housings, higher quality construction material, etc., but the water quality that comes out is the only thing that mattered to me. I think these units are another piece of equipment that goes way up in price because it says "aquarium" or "fish" on them.
I bought a 6 stage ---- model, not the one Kahnsell bought, for $80. I've had it for about 2 months and couldn't be happier with it. My original tap water is 447 TDS, after the RO stage is 10 TDS, and then after the DI stage it is 0 TDS.
FWIW, I've read in a couple different places that there are really only a couple of companies that make RO membranes and then companies buy them and sell them under their own name.
John

 

[wrassie86]

FWIW, I've read in a couple different places that there are really only a couple of companies that make RO membranes and then companies buy them and sell them under their own name.
John [/B]
Your right about that, but i also feel there has to be quality levels as with anything else.like factory seconds on membranes ect.Because i bet you will find that the R/O membrane cost more than the whole unit you bought from ----.same as mine.
But as stated ubove after running a HI-S model for the last 3 years.i see a huge difference in the way my tank reacts to not not having a HI-S model.
But the big thing is when i drop the $100 for the kent HI-S membrane.I still will have paid about $150 less then the compareable 4 stage unit from kent or pinnacle.

 

[johnny5]

I got an "aqua safe" reef model off of ----, it works great. <1.0 tds, I use it daily for topoffs. Its been flawless for 4 months, very affordable too.

 

[beth]

Originally posted by golfish
And some RO membranes are better then others. It wouldn't shock me to see a unit off ---- produce a high TDS. I have a buddy who bought one from ---- 4 months ago. He said it was zero up until last week, now its 150+...
The old saying "you get what you pay for" is something people should take note of.
What membrane brand do you use? What I have found is that who ever "manufactures" the RO, it really is the quality of filters that counts. Look at the manufacture of the actual filters.

 

[sandman12]

u probably got the aqua safe unit right? I got the same one. THe last filter has carbon resadue and cuases the TDS to read wrong. Test the water coming out of the filter right before the last one. I just had the same problem 10 min ago.
BTW: NO MORE TOP OFFS!!!!!!!!!!!

 

[krustytheclownfish]

Sandman12 makes a good point. That could very well scue the results. I don't know. I forgot to mention that right now I don't have the 6th stage(the last carbon filter) hooked up. From my understanding, that stage is supposed to improve the taste of the water for drinking but I'm not drinking it. I'm just using it in the tank. I figured it was just another filter that I would have to spend money to replace so I disconnected it for now. Oh, I too am using the aquasafecanada model.
John

 

[bang guy]

RO Membranes are stored with a gel like coating to prevent them from drying out. It takes 10 - 15 gallons of water to flush away this gel. Don't use the first 15 gallons for anything....toss it.
The typical RO membrane will only remove 70% of Phosphate & Silicate. I would expect to see a significant reading on a TDS meter. That's why regular RO membranes should be followed by DI rosins.
The Hi-S membranes remove about 95% of Phosphate & Silicate so DI is optional.

 

[kahnsell]

After tossing the first 35 gallons, my TDS is now reading 0. So the unit seems to be making pretty good water. However, I have not tested the water for silicates... I will do that soon.
So far, I am happy with this unit. However, I do not agree with the "you get for waht you pay for" argument. Especially since it is obvious that all fish stores and even on-line sites have huge mark up on fish equipment. If you buy the unit from a company that actually manufactures the RO unit, you will definitely get a better price than any fish store or on-line fish site.
I think that it is truly unfortunate that hobbyists are consistently gouged by wholesalers and lfs', but that is a separate issue.

 

[ffishermen]

bump,
how is the unit doing now?

 

[kahnsell]

Made water last night. After tossing the first gallon of water, TDS reading of 0... all is good. I never checked the silicates though...