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Any one have advise on Kati-Ani ??

:)

I think most people would feel comfortable doing it themselves once they've seen it done one time. It's not hard to do and as long as you are careful the process is very straight forward. Anyone who has ever worked around acids before should have no problem. If the whole acid thing scares you then there is always the 6 pack for service offer as long as you help me drink em. :)

You can also pick up a couple of extra cartridges and the resin in bulk. So you can use a few of them up before getting them recharged. I do this myself. Use them, then bulk recharge them all at the same time.

Carlo
 
I myself wouldn't do that. The reason being is that you are going to feed more polluted water to the Kati-Ani unit thereby use up the resin more quickly.

What I'd do (actually have done) is remove the DI cartridge from your standard RO/DI and add in a second/third carbon block that is half micron sized. You may want to re-tube it so the "DI" cartridge is before the membrane. Then have the good water coming from the RO/DI unit fed into the Kati-Ani unit. You could remove the carbon from this unit and add a standard DI cartridge. So it would end up being Cation, Aniion and Mixed Bed Resin. The mixed bed standard cartridge will last a long, long time if everything else is working correctly but it's there just in case one of the other resins gets low and you aren't aware it needed charging.

For anyone interested is seeing what's involved in recharging the resins malulu is bringing this unit over with him to the meeting so I'll be recharging it for him. Anyone interested is welcome to watch, learn and see how easy it is to do.

Carlo
 
In regard to running membranes in series (waste from first feeding the second membrane) - there is a misconception in the hobby that this is a easy way to reduce the amount of waste water. In some situations this is true, but not in most.

Remember that membranes plumbed in series perform like a single, long membrane. Recovery rates should not change from the 20% (4 part waste:1 part permeate) folks are accustomed too. If you have softened, or low tds feed water, you can get away with a bit lower ratio. If you have higher tds or unsoftened feed water, raising the recovery (operating at a lower waste:permeate ratio) will reduce the life span of the membrane.

If you want to reduce the "waste water" produced by your RO membrane, check to see that your waste :permeate ratio is no higher than 4:1, even during the winter when your tap water is cold; or use softened water. Or, depending upon how badly you want to save water, consider the trade off between less waste water and a shorter membrane life.

Russ @ BFS
 
I'm not sure where the misconception you mention comes into play. Running the membranes in series will by it's very definition reduce the amount of waste water by the specific waist/effluent ratio you run on the additional membrane.

As far as what ratio to use. Almost all manufactures recommend 4:1. In practice I don't think many people are going to see premature membrane failure if they lowered it to 3:1 or even 2.5 to 1 especially if they manually flush the membrane at the end of each run. I know guys who run membranes at 1:1 but make sure to manually flush for 1 minute at the end of each run and there membranes last just as long as anyone else's.

Part of the key as you mentioned is what your TDS starts out at. If your tap water is under 100 you could probably go 2:1, under 200 at 2.5:1, at 250 3:1, at 300 3.5:1 and anything over 400 at the recommended 4:1 without getting premature membrane failure (assuming you backflush).

One manufacture (Spectrapure) has (or is coming out with) an RO/DI unit that runs with zero waste most of the time. It's computer controlled and it monitors the status of the membrane. It will flush the membrane as needed and do a flush at the end of the run. More or less just like what we can do manually.

I suppose it's also worth looking at how often you are willing to replace the membrane you are using. If you would have normally had to replace it every 4 years but because you run low waste water output have to replace it every 2 years is that going to bother you? Some people won't want to do this while others wouldn't care if they had to replace it every year. I'd much rather save on water waste as it costs more in the long run if you don't have a use for the water. In these parts most towns charge you sewage based on your water usuage so it's a double bill for each gallon used.

Carlo
 
Sounds like you've got a good grasp on the situation. :)

The issue comes into play when either a vendor, or an end user adds a second (for example) 75 gpd membrane in series, joins the waste lines, and uses a single restrictor designed for a 75 gpd membrane.

This configuration yields the functional equiv. of a single 150 gpd membrane with a flow restrictor designed for a 75 gpd system.

Does this configuration produce a less waste water than a properly configured 150 gpd setup? Sure.

Is it a good thing to do for the average user? Probable not, except in cases where you are using softened water, and or low tds feed water, and or you are willing to replace membranes more often than would have been the case.

Russ
 
I'm not sure I follow you. How do you run in series but join the waste lines? That would have to be in parallel because otherwise you'd be running the waste from the 1st membrane into the 2nd membrane with only the waste of the second being true waste. You would join the good effluent from both units however.

In a parallel setup you would need two restrictors but in a series setup you would only use one restrictor. In series the restrictor would come after the second membrane. The would give both the first and second membrane the back pressure they need to perform properly.

Of course I'd say you have a good chance of needing a new restrictor anyway as most units I see don't come with a proper resistor. What works in a lab at 75F with 60 gph water pressure hardly ever works properly in the home and the flows are typically not running at 4:1 (if that is what you are shooting for).

I very much like adjustable restrictors for this very reason since it allows you to dial in the flow both during the winter and summer as they typically change.

Don't feel bad Russ, a lot of people who sell and manufacture RO/DI units don't quite get the little nuisances about running membranes in series or how much you can actually tweak them without causing any membrane harm or water degradation.

I've actually cut my membranes open, looked at them under a scope and have had tests done on them to see what mineral buildups have occurred. When I replace my membranes I almost always chop them and give them a good look under a scope to see how they look since I run a much lower waste ratio.

Carlo
 
You're right of course, I wasn't very precise in my wording. What I intended to say was when systems are configured in series, and what was originally two concentrate flows become combined into one (by way of the concentrate from the first flowing to the feedwater port on the second), you have to use a different flow restrictor than what was used on the first membrane before the piggyback system was added.

Part of my point is that there are vendors and end users who don't change the restrictor (and should).

Russ
 
I don't really agree with that. If the restrictor is good for one membrane it should work just fine for two membranes as the backpressure doesn't really change much. If you change the restrictor (and it was correct for 1 membrane) to something with more flow you do yourself a disservice as you actually increase the waste ratio a lot on the 1st membrane and the second membrane isn't seeing the correct backpressure it needs to operate properly. Normally you want to go the opposite direction and tighten up the restrictor as I mentioned earlier to reduce the waste ratio which normally work just fine (within reason). If you throw a couple of meters inline on the different lines you can see the pressure changes with different resistors.

I think part of the problem with RO/DI units in general is that they come with different flow resistors. I've seen 75gpd units for example come with everything from a 600 to a 1000 resistor with most being in the 800 range.

The restrictor of choice has a lot to do with water temp and pressure. If you warm up the water by running it through a coil in your sump or use a booster pump it can make your choice of restrictors different too, hence why I like variable resistors you can tune for your environment.

Carlo

PS, you can disagree with what I just said and I think that's OK since you sell these units and shouldn't advocate running them in a way the manufacture didn't intend them to be used. :)
 
I saw Phyl this weekend and she said I should address this thread. Artisan Corals LLC is the North American distributor for Kati Ani De-ionizing units. I was asked to speak at an upcoming meeting and answer questions which I will do. I read the posts on this thread and will try to address the highlights below.

A typical RO system alone will reach between 96-98% purity and with an add on DI cartridge, you will achieve 99% purity. With the Kati Ani units you will achieve 99% purity without the prefilters, membrane, etc. In other words, it completely replaces the RO system at a significant cost savings. The resins can be regenerated over and over lasting 30 years now in some units in Europe. It is true that you can use prefilters and RO membrane before the De-ionizing resins to extend the time between regeneration, but that costs much more than the regeneration costs.

There are five model sizes offered and the model number refers to the liters of resin. The model 1 costs $227.00 and purifies 380 gallons per day. There is no wrong size model to use; it is all a matter of how much time it takes between regeneration. A model 10 lasts ten times longer than a model 1. A model 1 costs about $1.30 to regenerate and a model ten costs about $13.00. Either way your operating cost to regenerate per liter is around $1.30. All models purify 380 gallons per day and take the same length of time (about an hour) to regenerate.

I provided a cost comparison on my flyer which one member questioned. My assumptions were clearly defined so that anyone could adapt the calculation to their specific situation. I will be shipping my largest model to a marine aquacultural greenhouse in Alabama this week. We went through three versions of a cost analysis comparing Kati Ani versus his very efficient commercial RO system. He agreed that the cost of the Model 10 would achieve a payback in 14.5 months with a $675 per year savings thereafter. I can erase the company name and e-mail the analysis to anyone who is interested.

Regeneration of the Kati Ani unit is fairly straight forward as Carlo stated. I do provide a regeneration service, but Carlo offers a much better deal!! I am working with Germany to improve the poor translation of the manual. I agree with Carlo that once you see a regeneration, you will probably do it yourself thereafter. The chemicals are strong and you must wear protective gear and pay attention. The Kati is regenerated with 6 parts water and one part Muriatic Acid. The Ani uses Sodium Hydroxide (Lye) in a similar dilution. The outflow of both is captured in the same container and they neutralize each other before pouring down the drain. Supposedly you can drink it – any volunteers?!?. Come on, they are only made up of Hydrogen, Chloride, Sodium and Oxygen.

Kati Ani has always been known to take out Chlorine as it is a basic chemical element. Chloramines are becoming more prevalent in municipal water supplies and are a compound chemical reaction between Chlorine and Ammonia. I double checked with the manufacturer and they emphatically state that Kati Ani resins will remove Chloramines as well as Chlorine without carbon prefilters. If any member has a high end Chlorine test kit, we can test for this. The only limitation the Kati Ani has is with some pesticides. If you are purifying drinking water, this is not an issue. If you are using a shallow well in a farmed area for a greenhouse operation, this may be an issue.

One astute member brought up the fact that you can regenerate the Ani in a different way [with salt, washing soda, and a small amount of lye to set the pH level] to continuously buffer the tank. You can set the pH in the regeneration process to say 8.5. The Ani unit placed in circulation will maintain the 8.5 pH in the tank for a long period. I will be trying this on my own tanks very soon and will report the results at a future meeting. This feature has never been publicized in the US, so it could be a major benefit to many marine aquarists facing high or low pH issues.

Kati Ani has been very popular in Europe since 1974. Many of our pioneer reef aquarists have used the Kati Ani for decades (at least three speakers at MACNA). They will all say that it is because of the high quality German resins – which you pay for. If you need more information, you can look at two web retailers who provide a decent amount of information online: www.premiumaquatics.com and www.thefilterguys.biz. I promise to pay closer attention to the club forum and answer any further questions more promptly.

Thanks for reading this tome.
Bruce
Artisan Corals LLC
 
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