RO\DI Questions

[Sculpin]

1) After a several uses the resin container starts to show some gaps. Is it ok to allow channels to form, or should I top off the container with additional resin?

2) The filter turns brown after a few uses, and then gets darker and darker. When should I replace the filter? I've read posts about monitoring the water pressure to know when to change the filters, but my system doesn't have a pressure gauge installed. Is there an easier way to tell or estimate when I need to change filters? E.g. after 500 gallons of water, or after the resin changes color?

In case you are wondering what type of system I own, here is a link on ebay of a similar system:
http://cgi.ebay.com/AQUARIUM-REEF-R...in_0?hash=item2ea6eb103a&_trksid=p3286.c0.m14

Thanks, Sculp

 

[Chichas01]

I think the membrane is suspect. I've heard some bad things about membranes that claim more than 100GPD but can't point you to anything specific. I think 'Scooterman' (???) knows a bit more about these.
I'm also sceptical about their comment that the GE membrane is better than the DOW Filmtech. I'm not a fan of anything GE right now, but that's another story.

 

[Scooterman]

Usually I pack the DI resin tightly to prevent this from happening, I would think you should pack it so you get complete filtration.
Which filter your talking about that turns brown? If it is the floss filter, it would be normal, when it stops up production will start dropping off. Lots depend on the water quality your getting in before the filtration unit. Is it city water or well water? Input pressure is very important for these systems to work properly also, If your input water pressure is lower than 55 psi production will be lots less. Usually you buy the color changing DI resin to help you determine when it needs to be replaced, it would turn brownish to yellow color when it starts being used up. TDS meters & water pressure will help you determine when to change your filters, along with production rates when they drop off. The RO membrane should last you a few years before needing replacing unless you have issues with water like maybe well water. If you back flush the RO membrane it will help it last longer.
for more reading try this website. http://www.thefilterguys.biz/filter_packages.htm

 

[burning2nd]

REguardless of how tight the resin is packed the effect will be the same..

but packing it tighter will produce longer life,

as for the color changeing resin.. Ive come to the same problem... the resin changes color quickly... this doesnt mean the resin is no go.. it means that your getting a large amount of co2 thur the filters....

the best bet is to rely on a Duel tds meter that will just let you know when its no good...

are you on well water? not that this matters. but normaly house's have 30-60 switchs for the pump.. so you will hardly be above 55psi... Doesnt mean your RODI will not work..

IMO monitor your input and output of tds's on the unit... you could go a step further and montior inbetween the units..

 

[Sculpin]

Thanks for all the responses. To address a few of the questions:
1) The filter that turns brown is the floss filter. I know that’s normal, I just wasn’t sure how brown to let it get before changing. Sounds like judging this visually isn’t going to work.
2) I live in Redmond in new construction so I’m not using well water and I’m guessing the water pressure isn't a problem.

Sounds like the TDS meter is the best way to be sure.

Thanks, Sculp

 

[beoks]

you can find tds meters fairly cheap well worth the 39.95 you can prob find them cheaper if you look around too

http://www.finsdepot.com/product/DTY-235653