Do I need to replace all the cartridges and the RO membrane in my filter?

[kwajtrader]

<span style="font-family: Calibri;">I&#8217;ve had a Kent Marine Maxxima Hi-S 60gpd for 1-1/2 years and the TDS meter has been reading 0 at the output of the DI cartridge since day one. The flow dropped significantly about 9 months ago and I replaced the pre-filter cartridges and everything was back to normal again. I have the filter hooked directly to a float valve in my sump to keep my tank topped off, and this past week, right before leaving on vacation I filled a cup of water and noticed a strong rubber smell. I immediately checked the TDS and it was at 45 at the output of the DI and 55 before the RO membrane. I pulled the DI cartridge and it had a strong rubber smell, but water coming out of the RO membrane smelled normal. The RO membrane doesn&#8217;t appear to be filtering much in the way of TDS. I&#8217;m assuming that I need to replace everything at this point, but since I&#8217;ve never flushed the RO membrane, before I replace the three cartridges and the RO membrane I thought I&#8217;d check to see if I overlooked anything.</span>

 

[jennm]

Kent has instructions on flushing too.

Lifespan of a membrane depends on the quality of source water, the amount of water it's processing and how well the prefilters are kept up.

Change the prefilters more often, prolong the life of the membrane.

I have everything you need *if* you do indeed need to change it all out.

Jenn

 

[kwajtrader]

Thanks. I'll try flushing it and see if that works. If not, what should I replace?

 

[jennm]

Depends what results you get after flushing.

If you haven't changed the prefilters and DI, I'd probably change those for sure. Membrane is a maybe - change the prefilters and DI and see what you get for TDS. The DI comes after the membrane, so it being spent isn't going to adversely affect the membrane, just won't effectively deionize whatever is left in the water after the other 3 stages... but the sediment and carbon filters are the most important ones to keep clean.

Jenn

 

[grouper therapy]

After 1 1/2 years I would change all filters and the membrane. Even if the flushing lowers the tds of ro water ,I don't think it will last since you have not done it regularly . The DI resin can catch most of the tds after a semi efficient membrane but will become exhausted much quicker. I would incorporate a solenoid and a timer in your ato setup for two reasons.
1.To reduce the risk of overfilling by only allowing the water flow a couple times a day for only a few minutes.
2. To reduce the time your rodi unit is running. If you have only a float valve on the ato more than likely your system is running 24/7 at a very slow rate which will reduce the life of the membrane.
I'd run by Jenn's and just get all new filters and membrane.
Sorry Jenn I just repeated part of your post slow typing

 

[mustangcaleb]

im going thru the same thing right now, my rodi is about that age. my prefilters look disgusting but my tds still says 0 ppm. but curious, are filters filters? is it that simple? or do they come in different sizes and all? my rodi is a filterguys 5 stage.

also if a filter is a filter, and they are all the same size, is there a brand or style that you guys recommend over any others?

 

[jennm]

Most units are a standard size. I've seen a couple of "off brands" that had uniquely sized cartridges.

Most of the replacement cartridges and membranes are similar. Membranes - I've seen different "brands" that looked identical in every way except the brand name label and price.

The sediment filter usually comes in 1 micron or 5 micron. I typically carry the 1 micron - can't "see" a difference from one kind to another.

The carbon cartridge can come in granular or "block" style - I use and carry the "block" - again, all brands look similar.

The DI cartridges can be different, some use refillable ones and buy bulk resins. I use and sell the 'mixed bed' resins - anion and cation resins together in one cartridge.

If you have a 5-stage you likely have either 2 micron filters or 2 carbon filters - usually that extra is a second carbon block.

Jenn

 

[mustangcaleb]

just looked at filter guys site:

<span style="font-size: 12px">All systems are made to order with clear 10" canister housings </span>
<span style="font-size: 12px">Stage One NSF rated 5 micron poly sediment filter </span>
<span style="font-size: 12px">Stage Two 5 Micron Matrikx NSF rated CTO/2 carbon block filter </span>
<span style="font-size: 12px">Stage Three 0.6 Micron Matrikx NSF rated +1Chlorine Guzzler carbon block </span>
<span style="font-size: 12px">RO membrane 75 GPD Dow FilmTec </span>
<span style="font-size: 12px">Stage Five in-line color-changing DI cartridge </span>

 

[jennm]

Yep, fancy names for them, but the same stuff.

They use a 5 micron vs. the 1 that I usually use/carry.

We have a 4 Stage Kent unit... 1 micron filter, 1 carbon (CTO/CFCE/Matrix - whatver), 2 membranes (piggyback, both do 100 gpd) and then a DI mixed resin - and yes it changes colour when exhausted.

Jenn