Hydroxide based or aluminum oxide based phosphate pad

[ReeferRob]

Hi Bob

We were having a discussion about controlling algae growth on frag plugs, and a member brought up the point of using a media pad to help control some of these excess nutrients.

Could you possible tell us the differences and or suggest the one that would be best suited for our situations?

Thank you

[Sir Patrick]

Tagging along!! I have always looked at these pad as inferior to other methods available, but cant recall why???? Makes me wonder.......

Looking forward to hearing what ya got to say on the subject Bob!

[AZDesertRat]

Personally i don't think the pads have enough surface area for the media to adhere to so have very limited capacity to adsorb contaminants. The advantage of a GFO or GFH media is the amount of surface area both on its outer surface and in its pores. Much like carbon the surface area is tremendous. I would always choose a ferric oxide media over an aluminum based one due to aluminums tendancy to release contaminants when it nears exhausting while ferric oxide medias do not allow this. This hase been well documentd in the drinking water treatment industry where bothe these medias are adopted from and been used for years with things like arsenic and others.

[BeakerBob]

The pads work well, but do not have the amount of adsorption capacity that the granules have simply because they are impregnated on the sponge material. Using the granular material in a reactor is much more superior in terms of surface area and capacity.

I have used both, but I prefer the granular for a larger tank. If you need to remove phosphate in a small tank (<25 gallons), either do water changes or use the pad. If you have a larger tank, then use the granules, I have found that the sponge will trap detritus that will fall off when removing the sponge from the tank.

Al vs Fe is debatable. Ferric may aid in plant growth while aluminum will not. Both are industry standards. Fe is gaining more use for the reasons that AZDesertRat has stated.