We use DI after our RO to polish the water. What size filter does AAMI now recommend? We presently use a .2 micron filter. Thanks

Wouldn't DI ususally go before the RO?
We don't need DI so I thought I'd ask.

Any how, the current thinking is that we will go to ultrafilters. 0.2 Micron is now standard but the standard may change.

I use two 0.05 mic, I believe that is the new
standard for endo protection, especialy if you are using UV,

we use a .02micron filter in our loop. we have we also have uv.

Pete, do you no where it states that in the AAMI standards book? Thanks

Look in RD62 under definitions. They state that an ultrafilter is a membrane filter with a pore size in the range of .001 to .05 um.

You will need to go with ultrafilters (see mburgess definition above) if you want to keep endotoxin out ...... FDA guidelines for water systems include ultrafilters following DI and/or storage tank in any system. Same goes for UV - if you must have a UV light, you NEED ultrafilters to follow. Just be careful that you have the proper filters to handle the flow you need. You can't just take .2 filters out & put in .05; they won't be able to allow the same flow rates through them. Best to speak to a reputable water treatment pro to figure out what you'll need.

Sandie, If one has two 20" casings, switching to .05 is not a problem. Assuming there is atleast a 60 lb. head pressure coming from your booster pumps. I have had mine installed for over a year and delta has yet to go beyond 4 lbs. I Ozone these so there is very little if any build up. ,05 mics are very expensive but worth it.

I' glad you have made the switch successfully! I've long been an advocate of keeping ultrafilters in line - I just meant that we should exercise caution - that not ALL .05 filters (even though they fit in the housing) can be evenly exchanged for .2 filters. Flow capabilities are different for various pore sizes & I have seen flow problems over & over again in circumstances where someone merely exchanged .05s for .2s. Each individual who wishes to make the switch should make sure that the new filters can handle the flow they need before they put them in & end up with reduced flow!

I'm SO glad we have a forum for these discussions! Thanks, RenalWEB!

How often does the .05micron filter have to be replaced? they are really expensive

Most filter manufacturers recommend replacement annually; I know of many facilities that have kept them on line much longer, though. I always recommend, as the FDA also does that you follow manufacturer's recommendation. You may want to check out the membrane type ultrafilters, which may remain in line for many years. Initial capitol investment is higher, but longevity & efficciency is the key. They are also nice because they REJECT the bacteria & endotoxin, sending them down the drain, rather than retaining or "collecting" them as barrier filters do.

Please e-mail or call if you have any specific questions.

Sandie Monsman, Isopure Inc.
smonsman@aol.com
440-946-0540

Change the .05 mics annually if your budget allows. But an increase in delta pressures is the key as to when to change them out. I'd say 10 lbs as the very max.
Price, some where around $300.00 each. Keep in mind that they are 510K certified. And there is a cost that comes along with that!

With ultrafilters you also have to look at if you have no delta pressure drop. This can be that the filters have failed and also need replaced.