this has worked the best for me

Like some other reviewers, I have used almost every brand of Granular Ferric Oxide (GFO) on the market over the years and BRS's Bulk GFO is undoubtedly the best for the price with very little sacrifice in performance. I give it 4 stars for performance because if you are willing to pay significantly more for other brands, they will perform very slightly better using the same amounts. I plan on purchasing BRS's High Capacity GFO when I run out of the "normal' capacity to compare. I anticipate that it will perform at or above that of the "premium" brands and the market (earning it 5 stars for performance), but costing approximately 33% more, will probably lower it's "value" score for me to 4 stars instead of this product's 5 (or even lower perhaps).

In my experience (15+ years at reef keeping), the use of GFO is way under promoted compared to its excellent utility. I have found it to be as fundamental for ensuring optimal conditions and parameters as are skimmers, calcium reactors (or kalkswasser/2 part solutions) or activated carbon (I know, I know... many don't use AC, but I'm a believer in its use also). Looking at the big picture, using GFO is one of the least expensive "costs" in being a continually successful reef keeper. It controls a vital parameter (PO4) that can cause devistation quickly and in low amounts.

An important caveat to remember is that many have observed deleterious effects by too quickly lowering high phosphate values, especially with SPS corals.

However, once you slowly get your PO4 to zero or near zero, consistent, continuous use of GFO will make your glass-cleaning magnet feel neglected!

I use BRS's GFO in a canister filter whose only other function is for pumping my aquarium's water through a chiller and holding small amounts of activated carbon. I keep both the GFO and carbon "sequestered" within the baskets of canister filter by using PURA Filtration Pads" (that I cut to fit with scissors) for the bottom and top most baskets. The canister filter also adds a little more water volume to the system.

The results of using BRS's GFO in this way have been outstanding. The only issue is that changing the media is a little tedious, so I'm very interested in trying out on BRS's "GFO Reactors", which appear to work under virtually the same principle, but should be much easier and quicker when it comes to changing out the media. If the price is right, the next review that you see from me may well be on one of those products (hint, hint BRS). ;)

From previous reviews here and on other sites, I am not quite sold on the "suspension-type" reactors due to the need for accurate flow adjustment (more maintenance) to keep the granules from either breaking each other up or from clumping too much). Although, clearly, their use would be far more efficient.

You will be impressed with this GFO.

This item lowed my phosphates slowly as advertised. I will be buying it again to be used with my reactor. Don't forget there is a calculator on the site that tells you how much to add to your system.

I use the BRS RO/DI, reactor and this GFO i have no.. zero alge issues. for the money it is the best deal i could find. and its nice not having to worry about if it works or not. Piece of mind!

works great. I had hair algae

already seeing decrease in competing alge in my display

I use the granular ferric oxide in my MRC reactor and this stuff tumbles really well. I found it to be better in my particular setup than the high capacity because I have the extra space in my reactor and it ends up being cheaper.

Great Value, works well. Make sure you flush well.

I just ordered a gallon of this after trying it in my system. I was fighting cyno and since I added this it has disappeared. Great stuff good value a little dusty but that can be over looked

This GFO is a SUPER value compared to the competition. I've had nothing but good luck.

Great price on a wonderful product. This stuff dropped my phosphates to nothing. I highly recommend it

Is this stuff Faked?