Kessil

5 Year Old RO/Di Filters - Still good?

Mark SF

Supporting Member
I'm piecing together equipment for the new set-up and scored a 5-Stage Spectra Pure MaxCap-90 Day RO/DI yesterday for a great price.

The unit was built in 2012 but looks brand new, and so do the filters, however they have been partially submerged in water and in storage for many years. The previous owner used the system, but very, very little.

So, I fired it up yesterday and the TDS meters read "0." Do you think that I'm good to use these filters or will they need to be replaced? I won't be using this for drinking water. Also, after this period of time, do I need to "calibrate" the TDS meters and probes or am I thinking into this too deeply?

-Mark
 
Is it an inline TDS meter you're reading it from?

Bruce - It is from the TDS meter built into the RO/DI system, so it is inline.

This is the exact system, except that Spectra Pure has updated the membrane and some of the pre-filters - http://spectrapure.com/RO-RODI/RODI-SYSTEMS/MaxCap-Manual-Flush-90-GPD-RO-DI-System

My system has:

.5 Micron Sediment
.5 Micron Carbon-Block Chloramine-Eater
FilmTec 75GPD Membrane, 98% rejection
Max Cap DI
Spectra Pure Silica Buster

2x HM Digital dual inline TDS monitors

-Mark
 
Toss the filters inside put in new and good as new one.

I wouldn't chance it.


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What are the risks if I use the existing filters and they are producing "0" TDS? Just curious, if I can use these existing filters it would make this a really good deal, not such a good deal if I need to replace the membrane, pre-filters and 2x DI?
 
First, I harbor a distrust of inline meters. Get an inexpensive TDS meter to double check.
Second, 0 TDS is 0 TDS and SHOULD be fine, but this is one of those areas I'd err on the side of caution. New filters are less than $100.00 and it's cheaper to fix a potential problem outside the tank before it becomes a problem in the tank with livestock at risk.
 
First, I harbor a distrust of inline meters. Get an inexpensive TDS meter to double check.
Second, 0 TDS is 0 TDS and SHOULD be fine, but this is one of those areas I'd err on the side of caution. New filters are less than $100.00 and it's cheaper to fix a potential problem outside the tank before it becomes a problem in the tank with livestock at risk.

Thanks for the info. Should I replace all the filters, including the RO membrane? I agree with avoiding an issue in the future, such a shame as these really don't have much use.
 
Mike @Coral reefer is an expert on RODI systems and membranes. Let's see what he says. If the membrane was wet though for years I'd think it could have build-up, etc? Really not sure.
My fall-back position on these types of questions is what I call the People's Court answer. :) Judge Milian often tells the participants a phrase she was taught growing up (in Spanish) that transalates to "The cheap gets expensive." That's never truer than in regard to reef tanks.
 
TDS only shows dissolve solid I mean other stuff could still be n the water especially what was filtered on there membrane before. Going all new may cost you a few bucks but at least you know there is no other contaminants.


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@xcaret gave me an ro/di unit ( thanks!) that still had a membrane, but there was a tiny bit of water left in the membrane and it was stinky. I would recommend changing everything
 
Make sure you wash all the housing throughout with RO water as well, there are buildup in the housing that people tends ignore.


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One reason to change filters that old is the switch that most municipalities have made from chlorine to chloramine. You need to be sure that your carbon block filters will be removing both.
 
Membranes last a long time but if not used or flushed they are as good as gone.
Pre-filters should be changed when the product diminishes and/or TDS start rising.
Membranes when new, come sealed with a special preservative coating; when the new membrane is put to use, the first few gallons produced should be discarded.
 
I honestly don't know. Might be fine, but like others said, not that expensive to change them out.

I did the math - it isn't a few bucks to replace these filters, lol. More like $150 minimum and $230 for the premium stuff...

Membranes last a long time but if not used or flushed they are as good as gone.
Pre-filters should be changed when the product diminishes and/or TDS start rising.
Membranes when new, come sealed with a special preservative coating; when the new membrane is put to use, the first few gallons produced should be discarded.

Thanks for the info. So, if the membrane is shot, then I should see TDS creep once I get the system up and running and producing some water.
 
I wouldn't say $120


Thanks for the info. So, if the membrane is shot, then I should see TDS creep once I get the system up and running and producing some water.

I did the math - it isn't a few bucks to replace these filters, lol. More like $150 minimum and $230 for the premium stuff...
Where are you looking? That seems pretty high to me. How many stages?
 
Sure it's 150-230 but you wouldn't have to replace it for years and using new stuff.


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The membrane is the more expensive part but is also the longest lasting.
I’d replace the sediment, carbon first and check TDS; if you run a DI canister, unplug it to check the TDS and the water production rate. My guess is if the membrane is good, you should have a good flow and very low TDS which the DI would take care of.
 
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