RODI filters

hey all...I have a spectrapure maxcap180. I just started running it and it is a great unit. My only concern is when/how often to change out the media filters.

I hear people recommend anywhere from 3-6 months or after so many gallons. It seems that a gallon usage would be more accurate than a month rating. As some of us use much more water in a month than others.

I know there are some very informed water people on the forum, so I thought I would get some advice. Well, that and the fact that spectrapure is not the most responsive company.

So, who has a general guideline for RODI maintenance for me? Thanks in advance. It is greatly appreciated.

 

How dirty your tap water is will determine how long your filters will last, so the logical right way is to use a TDS meter. When you get measurable TDS from the filter, it's time to change.

 

i guess i am more referring to the pre filters and carbon blocks. I understand to use the TDS meter for the RO membrane.

 

really?? nobody? where are all the water experts when you need them!

It really cant be as easy as change them every 6 months. suppose, in that six months I use 1000 gallons of water and person B uses only 400 gallons. how would we possibly be seeing the same results??

 

From what I understand, sediment filters will just clog and will slow the rate of water moving through them. As for carbon blocks, they should have a listing of the number of gallons each type can handle on the spectrapure site and I would advise changing them out a little before you hit that number.

The one thing you have to remember is that because the carbon is before the membrane, it is processing all water, not just finished water, so the life of the filter is based on total water input (or RODI + waste water), not just RODI output.

 

If you have a pressure gauge, that would be the best indication. When you are making water, the pressure will drop slightly with new filters. As they become more and more clogged, the pressure will go down even more. Of course with less pressure, the RO membranes are less effective I believe, so you would see a rise in TDS as well.

 

Straight from the Spectrapure website FAQ and many reef forums Sponsors Sections including this one:

GENERAL INFO ON REVERSE OSMOSIS
FAQ FOR REVERSE OSMOSIS
http://www.3reef.com/forums/spectrapure/4-simple-tips-increase-life-your-ro-membrane-75696.html
http://www.3reef.com/forums/spectrapure/when-do-i-change-my-sediment-carbon-filter-75695.html

I am anal about water quality so have two inline pressure gauges to monitor plugged filters and a low range chlorine test kit to monitor for chlorine breakthru. If you do that you can probably push the replacement frequency past 6 months as long as you take the time to monitor. I will also mention, not making much water or less frequently is almost as bad or worse than making lots of water and using it more often. Membranes need to be used at least every 10 -14 days and make 3-5 gallons minimum at a time to keep the system flushed out via the flow restrictor.

 

Thanks AZ. you were actually one of the "water wizards" i had in mind when posting this. I appreciate the links and the help.

 

also, while you're here. any advice on restricting the flow or increasing performance? I am getting real close to the 6:1 ratio. well past the 3:1 ratio i was expecting.

I am definitely going to upgrade to the UHE unit real soon here. I just feel terrible wasting so much water, right down the drain.

 

My DI filter from my Spectre unit is showing almost done around 200 gallons? This sound right?