A person on a Swedish online forum asked me why I didn't use an aluminum-based phosphate absorber instead of GFO. In his experience, Al-based absorbers were more effective in terms of phosphate. That's my experience too, but my latest ICP showed about 40 µg/L Al. That's the cutoff point for me and then I'll stop using Al-based removers for a while - the iron-based ones take Al too. I usually mix them normally
I follow the levels carefully
OCEAMO has analyzed the effect of different absorbers on macro, trace elements and pollutants
here. The study is done as a lab test - low flow, spiked samples and lots of absorbers so it probably doesn't fully reflect what happens in an aquarium but gives some guidance. It also includes Zeolite and activated carbon.
Al based media and GFO media
The second reason is that I have some trace elements that are starting to approach my upper cut-off value - want to bring them down a bit. GFO (the iron-based one) has proven to be very effective at this.
Al-based and GFO based
A third reason is that my iron-based (ATI) will be clogged at the end of its life cycle and since I plan to dose some Lanthanum just before I change the media, it will be an excellent fine filter for the Lanthanum/PO4 flocs
Once I have better control over my PO4, I will run mixed again - predominantly Al - if I run phosphate precipitation with solid media.
Read the article from OCEAMO - it provides excellent information
My measurements today PO4 0.52 and NO3 7.2 - Hanna Marin Master
Sincerely Lasse
