BRS High Capacity GFO

[Reeferdood]

I think this is a red herring, IMO. Bayoxide E33HC is claimed by the manufacturer to bind copper from drinking water, not release extra copper:

http://lpt.lanxess.com/uploads/tx_lxsmatrix/product_flyer_bayoxide_e33hc_en_02.pdf

"Heavy metal removal from drinking water, e.g., copper, lead, nickel, and zinc"


Iron oxide s never 100% pure. It will always have other metals in it. A few ppm of copper is normal in such materials, even when of a grade approved for food use (see below). Since the material is not dissolving into the tank water, there's little reason to think substantial copper is released. It is just part of the solid structure.

https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2016.4482

"Five batches of iron oxide black were analysed for the specified contents.12 They all complied with the specifications (iron oxide black expressed as iron: 68.5–70.9%; water‐soluble salts: 0.09–0.13%; arsenic: < 1 mg/kg; cadmium: < 1 mg/kg; chromium: 25–58 mg/kg; copper: 6–31 mg/kg; lead: ≤ 4 mg/kg; mercury: < 0.2 mg/kg; nickel: 57–117 mg/kg; and zinc: 32–65 mg/kg)."

Awesome, thanks!

 

[Randy Holmes-Farley Verified Community Expert]

So what would it take to add 0.1 mg/L copper to 5 gallons of water?

5 gallons = 19 liters

0.1 mg/L in 19 L is 1.9 mg of copper

If the GFO is 10 ppm (10 mg/kg) copper and is uniformly distributed in the material, you'd need to completely dissolve 190 grams of GFO.

I don't see that happening.

 

[Reeferdood]

So what would it take to add 0.1 mg/L copper to 5 gallons of water?

5 gallons = 19 liters

0.1 mg/L in 19 L is 1.9 mg of copper

If the GFO is 10 ppm (10 mg/kg) copper and is uniformly distributed in the material, you'd need to completely dissolve 190 grams of GFO.

I don't see that happening.

Yeah, likely not but I can tell you with absolute certainty that my tank along with 3 others tanks look much better since pulling this stuff offline. I won't be using it again. Perhaps Lc will be my phosphate lowering method from this day forward.
Perhaps it was a bad lot, not sure....

 

[Randy Holmes-Farley Verified Community Expert]

Yeah, likely not but I can tell you with absolute certainty that my tank along with 3 others tanks look much better since pulling this stuff offline. I won't be using it again. Perhaps Lc will be my phosphate lowering method from this day forward.
Perhaps it was a bad lot, not sure....

You sure you didn't drop phosphate too much or too fast?

 

[Reeferdood]

I think this is a red herring, IMO. Bayoxide E33HC is claimed by the manufacturer to bind copper from drinking water, not release extra copper:

http://lpt.lanxess.com/uploads/tx_lxsmatrix/product_flyer_bayoxide_e33hc_en_02.pdf

"Heavy metal removal from drinking water, e.g., copper, lead, nickel, and zinc"


Iron oxide s never 100% pure. It will always have other metals in it. A few ppm of copper is normal in such materials, even when of a grade approved for food use (see below). Since the material is not dissolving into the tank water, there's little reason to think substantial copper is released. It is just part of the solid structure.

https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2016.4482

"Five batches of iron oxide black were analysed for the specified contents.12 They all complied with the specifications (iron oxide black expressed as iron: 68.5–70.9%; water‐soluble salts: 0.09–0.13%; arsenic: < 1 mg/kg; cadmium: < 1 mg/kg; chromium: 25–58 mg/kg; copper: 6–31 mg/kg; lead: ≤ 4 mg/kg; mercury: < 0.2 mg/kg; nickel: 57–117 mg/kg; and zinc: 32–65 mg/kg)."

Last question....
I see it claims to pull heavy metals out of drinking water but, by adding salt to this mix could that change anything?

 

[Reeferdood]

You sure you didn't drop phosphate too much or too fast?

No faster than in the past with no issues.
I have used this GFO for a long time and never before had any issues.
I use a 1-3 ratio of ROX and GFO mixed together so I don't drastically change my levels. More for just maintaining and not lowering..

 

[Randy Holmes-Farley Verified Community Expert]

Last question....
I see it claims to pull heavy metals out of drinking water but, by adding salt to this mix could that change anything?

Yes, binding is typically less from seawater than fresh. But Dana still showed at least the type of GFO he tested to bind copper from seawater.

https://www.advancedaquarist.com/2012/2/chemistry

"For each procedure, a fluidized bed reactor (Two Little Fishies) was filled with 60g (dry weight) Aquamaxx Phosphate Out GFO."

"GFO (at least the brand tested) has a high affinity for phosphorus and silica and rapidly removes ortho-phosphate and silicates. Copper in the free form is removed, while ferric iron is added, though in a particulate and not soluble form. Zinc, manganese, and cobalt are also removed though concentrations never fell to critical concentrations"

 

[Reeferdood]

Yes, binding is typically less from seawater than fresh. But Dana still showed at least the type of GFO he tested to bind copper from seawater.

https://www.advancedaquarist.com/2012/2/chemistry

"For each procedure, a fluidized bed reactor (Two Little Fishies) was filled with 60g (dry weight) Aquamaxx Phosphate Out GFO."

"GFO (at least the brand tested) has a high affinity for phosphorus and silica and rapidly removes ortho-phosphate and silicates. Copper in the free form is removed, while ferric iron is added, though in a particulate and not soluble form. Zinc, manganese, and cobalt are also removed though concentrations never fell to critical concentrations"

Well, that pretty much sums this dilemma up.. When in doubt, toss in the good ole poly pad!