Using Phosguard on a lps/sps tank

[Randy Holmes-Farley Verified Community Expert]

Thanks for the follow-up, Randy

So it will still leach until saturation? What is the limit?

The saturation limit of aluminum in seawater is not a single number as it will vary with pH and alkalinity and other things in solution, and I do not have a way to look up the exact value.


In the article below, I gave this estimate based on known freshwater data:


The maximum solubility of aluminum at pH 8.2 in freshwater is about 2.7 ppm. That is, at concentrations higher than that, the aluminum will precipitate as amorphous aluminum hydroxide. I expect the solubility to be similar or higher in seawater, where complexation to organics may increase the solubility. Consequently, the solubility in both the oceans and in aquaria (as will be seen below) is apparently not typically limited by the solubility of aluminum hydroxide itself.


http://www.advancedaquarist.com/2003/7/chemistry

 

[Randy Holmes-Farley Verified Community Expert]

Can I use gfo in a bag in a hang on filter. I have a euphylia tank where I use phosgard like that. If gfo is better for the coral, I will switch!

If you have not noticed any issues with coral polyp expansion, especially when the Phosguard is new, I wouldn't change what is working.

GFO is often smaller particles and may not work well in a bag where water may not flow through it well.

 

[ecam]

thanks for the OP on this and to Randy. i just removed the phosguard i started using on tuesday. not worth the risk in my opinion

 

[powdermonkey]

Randy, years ago stated "I prefer the pellet GFO from BRS over Rowaphos due to size as I use it in a cannister filter, but there is little to no available data on performance issues".
Do you still have the same thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

Randy, years ago stated "I prefer the pellet GFO from BRS over Rowaphos due to size as I use it in a cannister filter, but there is little to no available data on performance issues".
Do you still have the same thoughts?

I still would prefer the pellets, but I don't think they are still available. At least I haven't seen them.

 

[Sangheili]

In my opinion, GFO is the best for phosphate remover unless your tank has Tridacna clams.

 

[DFW]

I still would prefer the pellets, but I don't think they are still available. At least I haven't seen them.

About half way down this page they show to have pellets. Is this the right stuff? GFO and Carbon

 

[Randy Holmes-Farley Verified Community Expert]

About half way down this page they show to have pellets. Is this the right stuff? GFO and Carbon

Yes, that looks right, thanks! In my application (a canister filter) I think pellets work better. I'll probably get some there next time.

 

[DFW]

Yes, that looks right, thanks! In my application (a canister filter) I think pellets work better. I'll probably get some there next time.

Thank you! Shouldn't that work fairly well in a bag, in a hang on filter, too?

 

[Randy Holmes-Farley Verified Community Expert]

Probably, but the pellets (at least the ones I used) are still smaller than larger material like GAC or Pgosguard which more easily allow flow through a bag.

 

[ahmed.boomer]

Thanks for clearing this up. I use the two interchangeably depending on what's on sale. Has no effect on my corals. Personally I find that GFO is much easier to crush, and it takes a bit longer to rinse. Whenever I have someone else taking care of my tank while I'm away, I tell them to use the Phosguard just so they don't crush the media from not adjusting the flow.

 

[Randy Holmes-Farley Verified Community Expert]

As long as you see no issues with either one, that seems like a fine plan.