Vince, Yep, muriatic and HCl is the same. HD/Ace tends to have it if the neighborhood has swimming pools. I posted some urls on the recharge process in this thread: http://www.bareefers.org/bar/viewtopic.php?t=847 My setup is based on the Aquarium Pharmaceuticals Tap Water Purifiers. Maybe not the cheapest way to go, but you can throw together a setup pretty easily with those. Also, I had gift cards to Petco, and it was convenient to use them up online for the TWPs. That Fish Place and Big Al's has the best prices on the TWPs and refills. Especially if you wait for a sale and buy enough to get quantity breaks from TFP. The basic process of recharging resins is that you add a bunch of concentrated lye solution to the brown anion resin column, stir periodically and let it sit, drain the lye, then flush a bunch of water through the column. For the blue cation column, you use HCl instead. If you have a mixed bed, you separate the resins by adding concentrated lye solution. The resins will separate due to their different densities. You remove the anion resin that floats, then you continue with processing the anion, drain, rinse, and pack it into an empty column. The cation resin that you left behind in the separation has to be drained and rinsed, then you add your acid, and continue the process. After you're done charging and flushing, you assemble your system and run a few gallons of water through it before you start collecting DI for your tank. I've seen in a few references that you supposed to run the water through the cation resin first and then the anion. I didn't see any explanation why, other than it works better that way.