RO/DI Life Expectancy

[GoVols1983]

How long do the individual filters in an RO/DI system typically last? I realize it depends on the water quality going in, but what is an acceptable range? I have a Coralife Pur-Flo II that has already started giving up after 150 gallons. Is this normal? I already planned to replace the filters with Spectrapure filters after they gave up, I just didn't expect it to be so soon.

 

[solitude127]

How do you know they gave out? And which filter gave out? Membrane, Sediment, Carbon Block or DI Resin?

 

[dunc101]

As you stated it depends on the actual unit, the amount of TDS that goes into the unit etc. With that said, I believe the "norm" is around every 3 months for the DI resin. Either 3 months or 6 months for the carbon and sediment filters (I forgot which it was), and around 2 years for the membrane I believe.

Also, I notice on my unit that it TREMENDOUSLY helps whenever I flush the membrane right before it starts making new water (it has seriously made my DI resin last twice as long).

 

[GoVols1983]

Not sure as it has no in line tds meters; however I do have a handheld tds and it reads 50ppm in the final water.

 

[GoVols1983]

You say every three months, but 3 months at what output. If I will only get 150 gallons out of any of the filters I am going to go broke pretty fast when I move to my 75 DT with a 40B sump. Well, that and all the other expenses that go along with moving up in reef size.

 

[dunc101]

Not sure as it has no in line tds meters; however I do have a handheld tds and it reads 50ppm in the final water.

Wow! That is very high! My water measures between 4-7 TDS whenever it enters my DI resin. I have a 5 stage RO/DI unit, fwiw.

 

[GoVols1983]

I really wish I went with the spectrapure to begin with.

 

[dunc101]

You say every three months, but 3 months at what output. If I will only get 150 gallons out of any of the filters I am going to go broke pretty fast when I move to my 75 DT with a 40B sump. Well, that and all the other expenses that go along with moving up in reef size.

As an example. I have a 90 gallon that evaporates about 1.5 gallons a day. I also change 2 gallons of water daily (automatic WC). I have been changing my carbon and sediment filters about once every 6 months, and DI resin about once every 3-4 months.

Recap:
- I use about 24.5 gallons a week of RO/DI
- 294 gallons in approximately 3 months
- 600 gallons in 6 months

 

[GoVols1983]

So basically double the life? What filters are you using?

 

[dunc101]

So basically double the life? What filters are you using?

I use a BRS 5 stage system.
Here are the filters I use.
http://www.bulkreefsupply.com/brs-5-stage-ro-di-replacement-filter-kit.html

 

[GoVols1983]

Not too bad on the price.

 

[shifty51008]

the main things to know if you wanna find out how well your system is running is:

tap water TDS
water pressure going into the membrane
TDS reading after the membrane (before DI)
and TDS after DI

if you can get us those numbers we can see if anything is wrong.

 

[DHyslop]

if you can get us those numbers we can see if anything is wrong.

Another way of saying this is:

If you have an RODI that doesn't give you those numbers, there's no way for you to ever know if it's working right at all.

 

[GoVols1983]

Yeah I am going to order a dual inline TDS meter as well as replacement filters and di resin. I'll check the originals and replace them if needed.

 

[that Fish Guy]

As you stated it depends on the actual unit, the amount of TDS that goes into the unit etc. With that said, I believe the "norm" is around every 3 months for the DI resin. Either 3 months or 6 months for the carbon and sediment filters (I forgot which it was), and around 2 years for the membrane I believe.

Also, I notice on my unit that it TREMENDOUSLY helps whenever I flush the membrane right before it starts making new water (it has seriously made my DI resin last twice as long).

How long do you Flush it for before making new water?

 

[Paulairduck]

What is your inlet water tds/ pressure

 

[dunc101]

How long do you Flush it for before making new water?

Usually about 5 minutes or so. As soon as the unit starts making more water, I get a TDS of right around 20 or so right BEFORE the DI resin if I do not flush my unit. After flushing for 5 minutes, I get a TDS of around 5-7 before the DI resin.

 

[GoVols1983]

So I should probably add a flush kit to my order?

 

[DHyslop]

Definitely. It's a $10 way to extend the life of a $35 RO membrane and $15 DI cartridges.