You might want to consider a 20x4.5 Big Blue filter housing with a GAC filter. That size filter is common and is reasonably priced. There are lots of choices. You want to look at the rate of water (GPM) in selecting an element. You can also leave the housing empty if you want to not have a filter element in there for a while. http://www.discountfilterstore.com/water-filter-whole-house-pentek-gac20-bb.html looks like a good filter if 10 GPM is enough for you.
The big version would be another tank that looks like your water softener. But this situation is probably temporary.
The big version would be another tank that looks like your water softener. But this situation is probably temporary.
