Lowering ammonia

[leebca]

First, the recent posters should realize they are posting to an almost 6-year old thread.

RO/DI systems very. Mine for instance gets water to about 4 ppm TDS which is suitable for FOWLR systems and a refugium of some robust invertebrates and plants. RO membranes vary in type and the size of particle they will prevent from passing through.

DI systems usually add something to the water, hence they are called exchange units. They pick something up and release something to take its place. A dual DI system is most effective, one tank to pick up positive ions; one to pick up negative ions. In this scenario, an RO unit is not needed and no recommended. Organics missed by the DI units can be removed by an organic filter. An RO unit can waste a lot of water and with today's green efforts, it goes against that choice.

You'll find more info in the post: WATER - Source and NSW

[Richard Boyd]

First, the recent posters should realize they are posting to an almost 6-year old thread.
An RO unit can waste a lot of water and with today's green efforts, it goes against that choice.

I don't think the age of the thread has any bearing on the content. I think I restarted this thread when I commented on it after I Googled "High ammonia levels in an aquarium" which I'm pretty sure it's safe to say is just as common in 2011 as it was in 2005 when the thread was started. As for "Green Efforts" who's to say that the water has to be flushed down the drain? If the article you cited is accurate, the waste water will only have a 25% higher concentration of contaminants than the original water, which would still make it safe for watering hardy plants, washing a car, topping off a swimming pool, etc...

[leebca]

Thanks Richard. Part of my concern is thread integrity, not wandering the subject. If water treatment is the subject you'd like to discuss, then begin a new thread for that topic. Visitors looking for that topic can more easily find it.

Of course that waste water can be used for a variety of other things, but it generally isn't. So much is produced for medium systems that plumbing for it in an average home doesn't use it all. Lastly, few hobbyists make the effort to capture/store it and install pumps to use it.

[Buckeye Field Supply]

First, the recent posters should realize they are posting to an almost 6-year old thread.

DI systems usually add something to the water, hence they are called exchange units. They pick something up and release something to take its place. A dual DI system is most effective, one tank to pick up positive ions; one to pick up negative ions. In this scenario, an RO unit is not needed and no recommended.

Hmm. Not sure where to start here.

The ion exchange resin used in this hobby release H+ and OH- ions, which join to form... water.

Separate bed DI configurations will provide inferior service compared to an equal volume of mixed bed resin. Unless you are planning on recharging your own resin, we recommend you stick with mixed bed resins (the cation beads and anions beads are mixed together).

Using a system that uses DI only, meaning not RODI - just DI, is not a practical solution for most people. Cleaning your tap water with RO first, and polishing the RO with wih DI is typically a better approach, especially if you are in the vast majority of the country which has triple digit TDS levels in your tap water.

Russ

[Buckeye Field Supply]

You'll find more info in the post: WATER - Source and NSW

From that old, closed thread:

The TDS of RO/DI water should be below 10. ppm. Rarely does this water make it below 2 ppm, with the average being around 5-6.

The TDS of RODI water should be 0 ppm. The RO stage should reduce the TDS of the tap water by atleast 90%, and DI resin in good condition should lower the TDS to 0 ppm.

Russ

[Buckeye Field Supply]

Also from that old thread linked to in the first post:

RO/DI - This is the acronym for reverse osmosis and deionized. Both are used together, usually DI first before the RO.

Just so people don't get confused - DI is used AFTER RO, not before. RO does most of the work, and the DI can be thought of as a polishing stage.

Russ

[leebca]

Thanks for posting Russ.

There are many different types of resins. If the resin pair being used is one of the cation-exchange resins and one of the anion-exchange resins, they they will release hydrogen and hydroxyl ions as you indicated. Assuming this, the incoming water will determine the quantity of each being released and it extremely rare that they are absolutely equal, leaving either a slightly acidic or alkaline resulting solution.

As far as what is practical -- it depends on the water that needs to be treated. This is not just a TDS matter, but what is actually in the water, now that antibiotics, recreational drugs, and fertilizers are showing up in som tap waters. I obtained a typical analysis of my tap water, then monitored it over a 4 month period with monthly analysis to get some idea on its variations. Two resin beds with a carbon polish is all that Anthony Calfo uses for keeping all of his marine life, including sensitive immobile invertebrates. Me, I chose not to do this due to the type of water I have access to in my community.

I have no actual data to know what is the majority of the country might be facing.

As to the order of the treatment, I'll certainly verify that and correct the post. Thanks.

[Buckeye Field Supply]

Maybe you are thinking of the use of Na+ form softening resin before RO?