Newly changed RO membrane... High TDS

C

ClownsRCoo

New member
Hello all,

I just changed my RO membrane for the first time since I bought my unit and my TDS out of the membrane used to be 4... I ran water through the new one for about 30 min to waste water and its reading 9.

Is there a long breaking period for new membranes where you have to just run a lot through them at first?
 
Let's back up a little.

What is your feedwater (tapwater) TDS?

What is your water pressure at the membrane?

What membrane (brand and model) did you install?

Russ
 
I don't know my feed water TDS off the top of my head. Haven't measured it since I set up the unit.

I run a booster pump and pressure is at 70psi

I bought (2) 75gpd Dow filmtec membranes which is what the unit had originally. If I kept everything the same I would think I should be able to expect the same results. 4-5 TDS from the membrane going to the DI.

I have run about 80g through the new membranes and it's staying steady at 7 TDS


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My latest membrane took about 2 months to come down to 8 from 14. I feel there's definitely a break in period.
 
This stinks because I'm not able to get 0 TDS water now. It's coming out at 1 after the DI stage. I have the color changing DI and it's only 1/4 brown so I know it's not exhausted. Even with only 7 TDS from the membrane. All other filters are brand new as well


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ClownsRCoo said:
This stinks because I'm not able to get 0 TDS water now. It's coming out at 1 after the DI stage. I have the color changing DI and it's only 1/4 brown so I know it's not exhausted. Even with only 7 TDS from the membrane. All other filters are brand new as well


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I have noticed once it starts to change you will see a rise in TDS. I change mine the moment I get anything other than zero
 
1 from DI with only 7 TDS in is either bad meter reading or exhausted DI. Is your DI vertical or horizontal?
If horizontal than u maybe just channeling and using bottom part of DI

And as other said 7 TDS after RO is fine....
IF you have 200 TDS tap and your membrane is 97% effecient that leaves about 6-7 TDS!
Incoming TDS could be higher...
Have you flushed your membrane?

I get 3 on avg out
 
Also freaking out about a few TDS is not worth it because you add tons of TDS when you feed and the fish POO!!:lolspin::fish1:
 
ptreef said:
Also freaking out about a few TDS is not worth it because you add tons of TDS when you feed and the fish POO!!:lolspin::fish1:
Click to expand...

But we know what that is. The problem with a reading of 1 is we have no idea what it is. I might be something we want,e.g. magnesium, of something we don't want, e/g/ arsenic.
 
Exactly. Chances are it's not something I'm already exporting in my tank or have the ability to export


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ClownsRCoo said:
It's vertical


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And a reading of 1 means it is no longer functioning and should be replaced. I no longer pay the extra for color changing and just go by my inline monitor. I also run 2 DI canister called 1 and 2. The moitor reads the TDS going from 1 to 2. When it reads 1 I move canister 2 into position 1 and replace the resin if the first canister and put it in position 2.
 
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