RODI question

[Candi]

Probably one of those things I should know... but I don't

I have the WaterGeneral RD 102 from ebay, been running for just over 2 years. I've replaced the prefilter & two carbon filters once so far, removed discolored and added fresh resin only a couple times. My TDS is 143 tap and 0 coming out (it was 2 but I swapped out about 1/2 the resin and refilled and we're back at 0)

So my question is, how often do you replace the filters... from their auctions it says every year for the three I've replaced once, so should I order new ones even though my TDS is still at 0? (the prefilter is dark, looks like I could use a new one but carbon filters look fine). How often do you replace the membrane... and how do you know when it's time?

Thanks for any input, tried to research a bit on RC but looks like most there dislike these units... I've been really happy with mine and saw quite a few of you here have the same one as well so hopefully you have more experience with it

Candi

 

[Hawkeye]

i'd probably change it whenever you notice the TDS change.

I would imagine a year is a benchmark and is dependent on each person's water. Like my wretched TDS is 345 out of tap - and I'd imagine my membrane is taking more of a beating then yours.

 

[mkreef]

You can not determine by color. You only need to replace your filter if your TDS reading starts to increase. Since your tap has a relatively low number (< 150), you are lucky in that you have a longer period between changes. Some with Tap readings of 400+, might need to change their filters every 5-6 months. Personally for me, I feel anything under 10 is "ok" because for me thats above 97% clean, > 10 its definelty time to chamge. Personal preference because nothing in this hobby is "exact".

 

[calaxa]

The prefilters you can tell from the color. The RO membrane, you will have to rely on the meter. If you get readings above 2, you probably need to change the resin. If you get readings above 10, the RO membrance and resin should be replaced (note it might be cheaper to buy a new unit than to replace a membrane). If you get color changing resin, you can use that to help guage when to change it.

 

[Candi]

Thanks everyone, it was mainly the carbon ones I was curious about and the membrane. I have the color change resin which is helpful. Since I'm still getting 0 TDS I'll just go ahead and change the prefilter for now (since it looks pretty bad) and maybe hold off a bit on the carbon filters.

 

[calaxa]

Candi,

The carbon filter is cheap and should be changed same time as prefilter. Carbon only lasts about 6 months to 1 year. Changing the carbon will create less work for the membrane and DI resin thus making their life expectancy longer, etc.

 

[stcreef]

All the prefilters should be changed at about the 6 month mark. Even if they look clean they can get stagnant.

For the membrane and DI, you need to measure The TDS going in and coming out. The membrane will have a percentage rating. When you no longer get that rating, its time to change.

For the DI, as long as the others before it are ok, as soon as you see anything above 0 TDS, its time to change. I would also recommend with DI, if you can refill, refill the whole thing, not just half. Depleted DI media can leach once its saturated. One of the first things it will leach is silica.

 

[pgordemer]

Candi,

The carbon filter is cheap and should be changed same time as prefilter. Carbon only lasts about 6 months to 1 year. Changing the carbon will create less work for the membrane and DI resin thus making their life expectancy longer, etc.

Actually, carbon's job is to remove Clorine as Clorine will destroy the membrane. Since Clorine will not show up with a TDS meter, it is recommended that it be replaced at least every 6 months.

 

[Candi]

Thank you for the education everyone off to purchase new prefilters & carbon filters now