Why pay too much? Bulk DI refills

[Lutefisk]

Hi folks,

I'm finally getting around to refilling my DI cartridges and want to share the wealth. In fact, I made this purchase planning on sharing it with other reef'ers. (How else could I use a full cubic foot of mixed bed resin).

This is high quality bulk DI resin and is used by many Reef Central users.

As you can tell from the price, I'm not trying to make money on this project - just to make a bulk purchase for friends and to share the cost.

I've packed some 4-pound ziplock packs that are good for four refills. (Ordinarily, DI cartidges sell for $19-20 each). I'm calculating that $5-per-pound would be a fair price (shipping was expensive). Using this bulk resin you can refill your cartridges for $5 a piece.

An important note - you must reverse the tubing on your DI stage when using this type of resin. This will change the water-flow to top down. Once reversed you do not have to change it again if you return to the expensive cartridges.

Why pay more?

Private message me if you are interested.

http://www.mindspring.com/~pogne/Images/ReefCentral/DIres.jpg


Paul

[smpolyp]

Paul do you know the reason why you need to switch the direction of the flow? And thanks again for your time. Rebecca and I are really enjoying it and looking forward to see you again.

[Lutefisk]

Turns out that people are saying that you don't have too if you FULLY load and pack the cartridge with resin. In any case, it takes a whole 30 seconds to switch the tubing.

The standard cartridge housing, using the labeled "In" and "Out" ports as labeled, flows water from the bottom to the top. What was happening is that some people were having the anion and cation resins separate (I guess they have different densities) as the water flows upward through the resin bed. This evidently degrades the effectiveness of the DI stage (the water needs to flow past the resins in a mixed rather than sequential fashion). The same people also reported that the mixed bed resins can form channels where the water passing through the cartridge is exposed to a smaller surface area of the resin. One of the bulk mixed-bed DI resin distributors recommends a top-to-bottom flow to prevent this separation.

The good news is that an inexpensive TDS meter will quickly reveal if there is any problem.

This type of bulk resin is the same used by labratories and other places that need to deionize large quantities of water (you don't think they use those expensive cartridges do you? :eek: )

Paul