Filter water with di and carbon only?

ravenmore · #1 07/04/2007, 03:25 PM

My RO membrane is shot and I REALLY need to do a water change today. Can I run my water through the sediment filter, 3 carbon filters, and a DI filter and get ok water? I'd just go buy ro/di but all the stores are closed. If I don't do it today I won't have another chance until next week and I don't want to wait that long.

dc_909 · #2 07/04/2007, 04:26 PM

It's better than tap, but I would wait.

virginiadiver69 · #3 07/04/2007, 04:34 PM

I don't see any problem doing that. Worst case scenario is that you will shorten the life of your di media but with a one time water change on a 75 gal it would not be noticeable.

csb · #4 07/04/2007, 04:52 PM

It should work fine. AP has a "tap water filter" on the market which is just a cartridge of carbon and DI resin. The resin becomes exhausted relatively quickly, but the output water is clean. Shouldn't be a problem in your scenario.

If you want, you could probably bypass the RO membrane just to make the process more efficient. You will be filtering all of the input water, so there would be no waste. Good luck!

attack11 · #5 07/04/2007, 05:07 PM

i use the AP filter, it works excellently with my tap water.

BuckeyeFS · #6 07/05/2007, 05:06 AM

If you do the "di only" approach, keep the water flow through the resin slow - you should shoot for something even slower than what you'd produce with a 100 gpd membrane (4 gallons per hour) - so try 2 gallons an hour to assure you have sufficient residence time. And yes - you'll burn through the resin quickly.

Russ

attack11 · #7 07/05/2007, 06:28 AM

5gl / 30mins is the fastest you should go with the filter. i usually shoot for 40mins. on avg it lasts me 3 months, or about 60gl. much cheaper than buying distilled and easier than talking my gf into letting me hook up an ro/di under the kitchen sink

ravenmore · #8 07/06/2007, 08:14 AM

thanks for the replies - I went ahead and did the water change and everything is fine. Yes, I trickled the water through it to maximize contact time. I'm hoping that it going through so much carbon (3 cartridges) before getting to the resin will protect the resin somewhat. I think its the chlorine that burns through the resin quickly? Its supposed to be color change resin but its still the same color it was when I got it, so I wonder about that. Oh well, its time to change everything else anyway.

BuckeyeFS · #9 07/06/2007, 08:27 AM

Prefilters (sediment filters and carbon filters) don't remove dissolved solids (TDS). That's done by the membrane and the DI resin. W/o the membrane, that entire job is left to the resin.

If you are not sure if you have color shanging resin, check the DI output frequently with your tds meter.

Russ