Two 10" cartidges in 20" housing?

[EricL]

I had a whole-house filter in my previous home that used this arrangement. In fact, I was under the impression at the time that it was designed to be used this way. Now, as I search for a filter for my new home, I see plenty of filters with 20" housings, but they seem to call for (surprisingly!) a 20" filter.

I'd much rather stack two 10" filters together, as they are much more widely available. Is there any good reason I shouldn't do this? It worked just fine in my old house; sorry I don't have a filter model number or anything. The water did not bypass the filter to any significant degree by using the two cartridges, but for all I know this is because that filter actually was designed to take a pair of tens instead of a single twenty.

So, will two tens fit in a 20" housing like I was doing in my old house? Or is there something going on here I need to know about -- like, say, a 10" is actually 9 1/2, and a 20" is actually 19 1/2, so that 10+10 no longer equals 20?

Thanks in advance for your help.

[Andy CWS]

Two tens will work just a well....providing the seal between the two filters is enough not to allow water to by-pass the filter elements materials. As the filters 'clog' greater pressure is exerted and water tries to find the path of least resistence and this is usually between the two filters.

There are special connectors for this purpose.

Cases of twenty inch filters are availble and your costs are reduced by bulk purchases.

Andy Christensen, CWS-II