Funny this should come up, I was just talking to someone at a LFS the other day, they were telling me that they run their RODI water into a storage tank and then through two GFO reactors before running into their mixing bin, I thought it was just a tad OCD...Either way, I just changed the filters a couple weeks ago, tonight I'll pull out my Hanna and check.

I just ordered some of this last week... http://caco3reef.com/nuclear-di-oniz...esin-cartridge

Is it the same as listed in this quote?

no thats just regular DI Resin. The stuff sprectrapure sells is specially formulated for different applications. I think they have 3-4 different resins based on your water quality.

So now 0 tds does'nt mean no P04? sweet, no wonder I'm over it.

If makes any help my last canister of my RODI is is filled with HC-GFO never though tested for it, but I will tonight and post the results. HC-GFO is labeled to remove traces of metals that is not pulled out by your regular RODI system

i would think that work quite well. Is there any issues with your ro water coming out brownish though? How long do you rinse out the gfo for your ro system?

I haven't done any testing but I do change the HCGFO every 3rd time I change the filter media I would say roughly every 3000 glns of water.
never had any problems with phosphates and my tank water is always crystal clear as some canreefers could attest to.

Sorry Tony as I feel hijacking your thread:biggrin:

Frankly this is all great information so I doubt he minds. So this HC GFO you're talking about, what kind of flow rate goes through that last canister? I would imagine its not rifling through there but doesn't it go through a bit fast?

it is compacted in the canister so the water flows fine as my RODI rated for as I recall 150glns/day