[r_wellwood]

Andrew,

I believe (but will have to check with Jayson) that the refillable cartridges for 19.99 at SWC are just an easily refillable cartridge - not a housing like on Aquarium Pros. Basically, if you look at any DI catridge at a retail location, imagine the plastic casing it comes in w/o the resin, and that is it (except w/ easy open and close for adding resin). This is what I have seen on the net.

So, for anyone who already has a RO/DI system (or other cartridge style filter), the refillable cartridge is a one-time purchase and the resin is cheaper in bulk. Thats it.

Jayson, if you are reading this can you confirm?

Ryland

**As an aside, the housing on Aquarium Pros site looks like any other regular housing with a tube added on the output - I imagine this tube is full of really small holes so as to not allow the resin beads to escape. This would be very easy to make, as the output on any standard housing usually has a lip for tubing to be attached to. Get a piece of PVC, drill some really small holes, and presto - refillable water housing for DI. This would be an alternative for anyone who didn't already have a spare housing as part of their RO system.**