Element Cobalt

[CoralClasher]

How concerned should I be with cobalt in my mixed reef and Macroalgae refugium?

 

[CoralClasher]

Bump

 

[taricha]

surprised to see 2 ppb Co described as "dangerous". Quick googling shows a tenth or a few tenths ppb to be values found in seawater. So yeah it's 10x higher than "natural" but I know nothing of levels of detrimental effects of Co.

 

[CoralClasher]

surprised to see 2 ppb Co described as "dangerous". Quick googling shows a tenth or a few tenths ppb to be values found in seawater. So yeah it's 10x higher than "natural" but I know nothing of levels of detrimental effects of Co.

Yeah if triton didn’t call it dangerous I would just let it ride. Maybe they are right and I should change some water and stop using ChaetoGro?

 

[blasterman]

I would like to see verification that they have gear that can detect 2 ppb of cobalt with that precision in the place.

More than likely the cobalt is coming from your salt mix.

 

[CoralClasher]

I would like to see verification that they have gear that can detect 2 ppb of cobalt with that precision in the place.

More than likely the cobalt is coming from your salt mix.

RedSea blue bucket salt. RODI water 0 TDS. I have been changing 20% a week for the last two months and haven’t over dosed ChaetoGro, just what they recommend.

 

[CoralClasher]

Everything seems fine in the tank. No real problems.

 

[CoralClasher]

Only other sources I can think of is Brightwell Razor. Anyone know what’s in that stuff?

 

[taricha]

Maybe they are right and I should change some water and stop using ChaetoGro?

This 100% accounts for your higher than recommended values of Co and Fe.
(But not Si)
@Dan_P might be interested in what Triton detects in the chaetogrow ingredients.

 

[Randy Holmes-Farley Verified Community Expert]

When I had my water tested by Triton, this was my cobalt comment:

"Cobalt (Co). Cobalt is present in natural seawater at roughly 0.006 µg/L. The Triton LOD = 0.4 µg/L), so having none detected may be fine. We cannot really tell much, unless there is a substantial excess."

FWIW, I do not know what level cobalt becomes an issue, and any answer is speculation since you do not know the chemical form of the cobalt that was detected at 2 ug/L.

 

[CoralClasher]

This 100% accounts for your higher than recommended values of Co and Fe.
(But not Si)
@Dan_P might be interested in what Triton detects in the chaetogrow ingredients.

I think the Si was from sponge excel a long time ago fighting sand Dino.

 

[CoralClasher]

When I had my water tested by Triton, this was my cobalt comment:

"Cobalt (Co). Cobalt is present in natural seawater at roughly 0.006 µg/L. The Triton LOD = 0.4 µg/L), so having none detected may be fine. We cannot really tell much, unless there is a substantial excess."

FWIW, I do not know what level cobalt becomes an issue, and any answer is speculation since you do not know the chemical form of the cobalt that was detected at 2 ug/L.

Will active carbon or poly filter remove cobalt?

 

[Randy Holmes-Farley Verified Community Expert]

Will active carbon or poly filter remove cobalt?

Some chemical forms, yes, and some likely not.

Cobalt is part of vitamin B12 and a lot of other organics. That will have very different chemical and biological properties than, say, free Co++.

 

[CoralClasher]

Some chemical forms, yes, and some likely not.

Cobalt is part of vitamin B12 and a lot of other organics. That will have very different chemical and biological properties than, say, free Co++.

Ah B12 just made me think about the Seachem “Reef Plus” that I’m also using. Sure enough it has cobalt listed ingredient. So I’ll cut back on the vitamins and ChaetoGro. Would you still recommend water changes to try to lower it or let it be?

 

[Randy Holmes-Farley Verified Community Expert]

Ah B12 just made me think about the Seachem “Reef Plus” that I’m also using. Sure enough it has cobalt listed ingredient. So I’ll cut back on the vitamins and ChaetoGro. Would you still recommend water changes to try to lower it or let it be?

I'd just to whatever you normally do with respect to water changes.

 

[Dan_P]

This 100% accounts for your higher than recommended values of Co and Fe.
(But not Si)
@Dan_P might be interested in what Triton detects in the chaetogrow ingredients.

“Chronic test results indicated that invertebrate and plant species were substantially more sensitive to Co exposure than fish. The chronic toxicity data were used to calculate a species sensitivity distribution, from which a hazardous concentration 5th percentile of 7.09 µg dissolved Co/L (95% CI 0.025–47.3 µg Co/L) was derived. Environ Toxicol Chem 2021;40:1405–1418. © 2021 SETAC”

https://setac.onlinelibrary.wiley.com/doi/full/10.1002/etc.4993