Just a little background...I am new to dialysis, 7 months, and am currently setting up a new unit. Call me Crazy!!! I took on the project after our hospital was unable to attract anyone to the director's position. Our closest dialysis unit is 50 miles away and I guess there was no one close with any experience. Right now I am trying to make water treatment decisions with my limited amount of water treatment knowlege and am getting so many different answers on what we should purchase. We will have a 6 chair facitly, off-site from the hospital, and will start by running 2 shifts M-W-F. I am getting so many mixed answers on 2 components of the system.
1. Direct Feed vs Indirect
Will one be harder to maintain than the other given we are only open 3 days?
We have 3 RNs, no techs and no full time biomed. I will be responsible for the bulk of maintaining the sysem.
2. Carbon tanks---backwash vs exchange
How often do you have to change the carbon in each? I have been told many different things. But the majority of answers have been--backwash every 6 months(because of the bacteria more than the carbon depletion) and exchange tanks every 3-4 months. I know this depends on the chlorine/chloramines, but I am just trying to compare the 2 tanks more than get an actaul time frame. I have been told that exchange is so much more expensive over time by one person and that it is not by others. I know it depends on how we rebed the tanks, but like I said, I am responsible for the bulk of the general maintanence of the system and will be, with a plant op person, doing the majority of the work. Is one giong to be less work than the other? HELP!!!!!

As for a RO we have and it is very easy to operate an Osmo 23G with 9 membranes (we have 18 stations). It also is very easy to clean and maintain(once a month is what we do). As for carbon tanks we have autobackwashable tanks with 9 cubic feet of carbon in each. As for rebedding up until recently we had only rebeded once in 5 years.And I don't know who told you that should be backwashed once in 6 months they should be backwashed everyday to prevent channeling in the carbon causing premature carbon exhausting. We were only open 3 days a week at one point and we backwashed our tanks on non treatment days and once we went to 6 days we started everyday. As for exchange carbons it is expensive our vendor in OKC charges us $315 a tank with 3.6 cubic feet this is the biggest they offer and the price goes down from there.

If I was you I would contact Don with Mar Cor Services,Inc 1-800-346-0365 he is a wealth of knowledge and will be of GREAT service to you. And hopefully Chuck will respond to you too he also is a wealth of knowledge. Good luck and if I can help anymore email me. Matt

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Get in touch with a well known water treatment company who are experiened in treating water for dialysis. Personnely, I would go with a direct feed system of RO and exchange tanks for the carbons.
The Osmonics 23G is what I have my facility and has been very reliable since the day we opened 4.5 years ago. I recommend exchange carbon tanks only because its simple and easy. Do a change out every 6 months regardless of breakthrough or not but, get a price also for backwashable carbons.

Thanks for your quick response!!!!
I was actually told I had to replace the carbon in the backwashable tanks every 6 months due to bacteria growth in the carbon.
When I told this person that someone else had told me they hadn't replaced thier carbon in their tanks in over 3 years they told me that was rediculous, so I thought maybe we weren't all talking about the same thing, but I think we are. When you say you rebedded the tank after 5 years, do you think when he says he changes his carbon in the backwashable due to bacteria growth, that is what he is talking about?

Tony,

I would go with a direct feed system, if you have an storage tank (indirect) you will have more bacterial/endotoxin problems on top of more components to breakdown.

When sizing the RO machine, you need to calculate the maximum DFR of all the machines, reuse (if being done) and making bicarb. After you add all of these things together, add an additional 10%. If there is even a remote possibility that your water needs will increase, you should make sure that the RO machine can be expanded.

As far as your choice of carbon tanks, backwashable is the way to go, they will pay for themselves in 6 months or less. Like Matt said, whoever told you that you need to replace the carbon every 6 months is probably either trying to make a mint off of you with exchange tanks or just dosn't know what they are talking about. If backwashables are backwashed nightly (even days of non-operation) you will not have a bacteria problem.

The rule of thumb for how long carbon will last before needing to be replaced is:

1 cf of carbon will treat 1,000,000 gallons of water with a total chlorine level of 1.0 ppm

Chuck

That's almost small enough to get away with portable RO's and PX carbon tanks. At least you wouldn't have to deal with the hassle of all the plumbing work. However, I think what everyone else is saying sounds good. I would also recommend the Osmonics 23G. They're good machines, not too complicated and easy to work on. I would also go with the backwashable carbon tanks. Much less hassle in the long run.

GTSCSS,

Thats a very good idea! I have an Osmonics Solo portable RO that will supply 3 machines at 500 DFR or 2 machines at 800.

Chuck

I would be careful with going portable, especially if your only open 3 days a week, most portables are not set up for auto running/flushing during down times. In our experince the portables are much more maintenance intensive than the larger systems, they are much more likley to have bacteria problems. I agree the 23G is good choice we have one with 4 membranes for 9 stations. Backwashable is the way to go, we just rebbeded ours at the 5 year mark and had not had any breakthru yet. Your source may have been refering to carbon tanks that are not consistantly run or flushed like ones on portable units(the guideline for my portables states minimum change every six months)

I agree with dman about the portable RO's we have 3 at our acute unit and I hate all 3. They are constantly going down and at least 1 of them every month has positive cultures. I have to redraw them 2 and 3 times plus disinfect them 2 and 3 times to get the cultures below AAMI standards. This is a huge thron in my side I spend more time on weekends with the RO's than I do with my family.LOL I would think twice about going portable and then think again i would not reccommend it at all. The Osmo 23G is a super unit and would satisfy you I think.