RO/DI Membrane question

[bigmac]

I'm getting organized to start another tank after a move into a new house. I have an ro/di system that I had running on my 90 gallon. My question is this; does anyone run theirs without the membrane which would then rely on the sediment, carbon and DI resin to purify the water? An experienced reefer told me once that he never used the membrane at all; due to the amount of water wasted.
Has anyone tried this?
Calgary water isn't really that bad; but I'd like to hear from anyone that has tried this.

[Myka]

You can do whatever you want to do. I think Calgary water is around 200-300 ppm out of the tap? DI resin will only remove up to 20 ppm, and it will burn out very quickly if it is indeed being fed water of 20+ ppm. Now, if you lived in the lower mainland where the tap water is often less than 20 ppm then running just DI is definitely a reasonable option. I wouldn't do it though. DI won't remove all the things that RO will, same that RO won't remove all the things DI will.

[FitoPharmer]

You could possibly do it in some places, like around Vancouver since I hear some people there are getting 1-10 TDS out of the tap. Use a TDS meter on your tap water. The higher it is the faster it will consume your deionization resin. Normally a membrane will drop your TDS to 4 or less at the cost of the waste water. If your TDS is +50 your resin will deplete very quickly. You have also interested me if anyone in a low TDS situation skips the membrane, and how long their resin lasts on average.

[FragIt Dan]

TDS in Nanaimo typically runs about 8ppm, if it gets above 15 I shut my system down and wait for the spike to pass (guess I am kinda spoiled here). I run a membrane and have had the same resin for well over a year (colour changing and is indicating it is close to done) and I go through a fair bit of water. I would expect to go through a lot of resin without a membrane and still not have clean water.
Dan

[whatcaneyedo]

There are some other alternatives you may want to consider. I've seen systems available which run two membranes for much less waste and others which return the waste to your hot water tank. If I had the room I would install a large plastic drum near the laundry machine and use all of the waste water for laundry.

I've been using RO/DI since 2005 because it gives me complete control over what goes into my tank. Think of it as risk management.

[tim the toolman]

In the years I have been using ro di I have never wasted a drop of waste water. I use it for laundry (especially washing filter socks) and watering house plants etc. just have a brute set up next to the washer and tied into that feed for my ro water.

[bigmac]

Thanks for the replies so far. I'd be very curious to see the TDS readings of the water after it was run through maybe two ro/DI systems (without the membranes in either). Therefore it would go through two sediment filters, two carbon filters and two resin chambers without passing through the membranes. It's an odd thought; I'm aware of that. Just curious if it would work and what the readings would be.
I'm not able to re-use the water for my washing machine as the tank will be in the basement and the washer is two floors above (or should I say it's too much work and it makes my head hurt). I'm not a fan of dumping it into the hot water heater as the extra energy utilized to heat the water isn't appealing.
I've also seen an article somewhere about baking the DI resin to recharge it (or was that just a dream I had). Anywho; I'll continue to do some more investigation and some testing once I'm closer to the new build.
Keep any comments or ideas coming.

[whatcaneyedo]

Here is one of the options I mentioned earlier, this system claims to reduce the waste of a standard 75gpd system by half. http://www.bulkreefsupply.com/brs-15...grade-kit.html

Some people claim to re charge activated carbon by baking it. But from what I've read that doesn't work. Apparently the true process requires pressure, steam and heat.

GFO can however be recharged with some harsh chemicals.