When to change RO filters?
 

I have had my RO unit for a year now, tds meter is reading 9, guessing its time to change filters?

I change mine whenever I get a non zero TDS. Ranges from 8 months to a year depending on how heavily I've been using it.

Ya, thinking this is what's causing issues in my tanks ATM...will pick up new ones tomorrow!

Certainly your output TDS is an indicator, but it also depends on how your system is put together (how many stages, pre filters, rating of the membrane etc), the TDS of your source water & how you run it.

If you have clear pre filter housings you have a visual indicator of how those are doing & being relatively inexpensive, they can be changed more often without worrying whether they are completely clogged or not. The more pressure (within specs) that your membrane sees, the better & clogged pre filters, including the carbon stage(s) all drop the psi before it gets to the membrane.

I use two pressure gauges on my system, one at the source showing house pressure & one at the RO membrane (after the pre filters). Whenever I run the system I keep track of the difference between the two pressure gauges. Once the split rises by a given amount, usually 3-4 psi, I change the first stage pre filter, a 5 micron. I run a 1 micron pre filter after that, followed by the carbon block which is rated for a throughput of thousands of gallons. I only recently changed the carbon black after a couple of years of use. Also keep track of total gallons through the system to give an idea of when the carbon is getting close to it's rated capacity. Just in case, I keep a swimming pool test kit handy that has strips which include chlorine detection.

A few months ago the TDS out of my DI stage started showing 1, so that's when I changed out the DI media & also the carbon block, since it was nearing it's rated thruput. I'm still on the same RO membrane since buying the unit new almost 3 years ago. With 210 TDS tap water, the 75 gpd membrane still gives me 1 TDS out 3-4 minutes after start up.

Regardless what your TDS is, if you are using this filter system for drinking purposes it is best to at least change it out every six months. Just to be cuatious, the bateria build up on the filters are eliminated this way. If you like the taste of the bateria then just follow your TDS readings.

How do you tell when you membrane needs to be changed?

My water coming in has a tds of 110, my last batch of water going out was at 9. I've got a vertex RO unit, no di. I haven't monitored the gauges at all, it has 2, but I never look at them....as for how the canisters look, I can't see a visible difference but again, probably not paying attention from initial set up.

I've noticed HA growing on my cheato and in my emerg overflow, plus I've I've an outbreak on cyano in my small tank, feeding habits haven't changed so I'm thinking it's my water.

I have not kept track of how much water I've produced but since setting up my 180 in feb, I'm making between 30-60 gls a week, depending on water change schedule.

Our fridge filters water and that's what we use for drinking water.

Changed out the carbon and RO, but didn't grab the prefilter. I'm running the unit anyway to flush the RO membrane, already tds dropped to 3 within minutes. Will grab the prefilter hopefully tomorrow.

Will not let it get this high again.:redface:

Little confused ...
When my RO water started to smell of chlorine, I immediately changed both my filters ... pre-filter and carbon filter
I saw no change in my chlorine smell after new filters ...

I was trying to finish my post before it got wiped out :smile:

You can get up to 6 months out of a carbon filter, and 3 years from a RO filter

It all depends on your usage ....

So, here's what I've learned ....

You get 3 months out of of your pre-filter, 3 months from your next stage, 6 months out of your carbon filter, and 1-3 years out of your RO membrane (depending who you talk to)

Good thing lots of members give us lots of information so we can gauge our filters ....

When your RO filter turns brown, you should change it;
When pre-filter turns brown, it's time to change it
When a Carbon filter turns black, it's well over-due
C'mon, don't ask when an RO membrane is past due ....