Why is the Extrax Phos cheaper than GFO?

[Crustman]

I know this stuff has aluminum in it and I hear good and bad things about it. The spherical beads work great in my reactor and I recently had a good batch of GFO get pumped out of my reactor into the sump. Had to siphon it out. Just list the pros and cons please.

[Crustman]

Observations, I have 3 Tridacna clams and they don't care if I use Aluminum or Ferric media. CBB is fine with it. Corals are fine.

[bertoni]

I would avoid an aluminum-based media. They have caused trouble for a lot of tanks with corals. I suspect that clams might be affected, too. This article covers the issue:

http://www.advancedaquarist.com/issues/july2003/chem.htm

[Crustman]

Thanks for this. I will switch to GFO if I notice any problems.