# Cobalt and Nickel



## jaypeecee (4 Mar 2021)

Hi Folks,

I'm trying to determine if two trace elements - cobalt and nickel - are required in planted aquaria. Neither of these elements are listed in the index of _Ecology of the Planted Aquarium*_. Referring to _James' Planted Tank**_, I see that cobalt is present in both _Seachem Flourish_ and_ Seachem Flourish Trace_. And nickel is only present in the latter of these two nutrients. Other current fertilizers, e.g. _TNC Complete_ and _APT Complete_ do not appear to include either cobalt or nickel. OK, so why am I asking about this? It's simply because both these elements are required by cyanobacteria (aka BGA). I am fully aware that other factors play a part in the growth of cyano, e.g. dissolved organic matter (DOM) but why add cobalt and/or nickel to our tanks if it could _potentially_ cause problems?

For anyone using urea in their tanks, the enzyme urease contains nickel.

Caveat: I am by no means an expert in the topic that I am introducing here. I am simply trying to get a more complete understanding of the factors that may contribute to cyanobacteria in freshwater aquaria. And if fertilizers play any part in this, that's why I've placed this thread under "Aquarium Fert Dosing".

*  by Diana Walstad
** James' Planted Tank - Comparison Of Traces

JPC


----------



## jaypeecee (5 Mar 2021)

Anyone?

Please.

JPC


----------



## John q (5 Mar 2021)

Probably not helpful but might stimulate discussion. 

Excerpt from an article.

Increase in growth (shoot length) and pigments (chlorophyll a, b and total chlorophyll) were detected at 25 µM cobalt concentration, whereas the growth and pigments were declined in 50, 75 and 100 µM.

Taken from this article.








						Assessment of cobalt accumulation effect on growth and antioxidant responses in aquatic macrophyte Hydrilla verticillata (L.f.) Royle - Biologia
					

Cobalt is an essential trace metal and plays a pivotal role in the growth of all living organisms. The exposure of cobalt in the aquatic environment is ubiquitous via both natural and anthropogenic activities. The present study was carried out to investigate the accumulation response of...




					link.springer.com


----------



## Zeus. (5 Mar 2021)

I am pretty sure plants need Ni, I di the maths and if you use tap water there is enough for the plants needs, Some folk using 100% RO water normally add the Ni in the DIY trace solutions, which is pretty easy. same for Co

As for Co a few commercial ferts do contain it , Seachem Florish, JBL proscape Fe and micro nutrients, Proflora Ferropol, Dennerle has it in a few of their 'complex' fert range also
Not aware of. 
IFC calculator does all the calculations for making trace solutions for both


----------



## jaypeecee (5 Mar 2021)

Hi @John q 

Many thanks for your reply and the attached paper. It seems that plants are very good at mopping up nickel and other heavy metals. And this is one of the reasons for the scientific interest in such plants i.e. for purifying eutrophic stretches of open waters - lakes, etc. This is a field in which @dw1305 has experience. The following is also of interest:



			http://www.plantphysiol.org/content/plantphysiol/62/4/566.full.pdf
		


This paper was first published over forty years ago!

JPC


----------



## jaypeecee (5 Mar 2021)

Zeus. said:


> I am pretty sure plants need Ni


Hi @Zeus.

Many thanks for your reply.

Whilst some 'complete' fertilizers and some trace fertilizers contain cobalt and nickel, there does not appear to be any consistency. It's almost as if some add cobalt and nickel because 'that's what we've always done'. I'm trying to get to the fundamental science behind the need for these two elements. Cos, if they're not needed by plants (or fauna), then eliminating these two elements might just help to keep the Blue-Green Menace (aka BGA) away.



jaypeecee said:


> For anyone using urea in their tanks, the enzyme urease contains nickel.



It's just dawned on me that plants must contain urease in order to hydrolyze urea. That being so, plants will need nickel as it is a component of urease. If I'm right, then the $64,000 question is......do aquatic plants need cobalt and, if so, why - and how much?

JPC


----------



## dw1305 (5 Mar 2021)

Hi all, 


jaypeecee said:


> do plants need cobalt and, if so, why?


Plants have a cobalt (Co) and nickel (Ni) requirement. Nickel is essential for plant growth, <"they aren't sure about cobalt">. 


> Nickel (Ni) is also an essential micronutrient for urea assimilation and N metabolism. Urease is an essential enzyme for urea assimilation in plants, and in cases of Ni deprivation its activity is decreased. In addition, glutamine synthetase is also involved in urea and N metabolism and it is influenced by Ni availability. Nickel is usually taken up as Ni2 +. Finally, although Cobalt (Co) is not an essential plant metabolism nutrient, it is considered as a beneficial element, participating in symbiotic N fixation. It is taken by plants as Co2 +.


One of the problems is that you are talking about a requirement in ppb (10^-9), so my guess would be that you could only effectively exclude them by using analytical grade salts (to add the other elements) and ultra pure DI water.

cheers Darrel


----------



## jaypeecee (5 Mar 2021)

dw1305 said:


> One of the problems is that you are talking about a requirement in ppb (10^-9), so my guess would be that you could only effectively exclude them by using analytical grade salts (to add the other elements) and ultra pure DI water.


Hi @dw1305 

So, what are we waiting for? 

OK, I give up. Let me turn this around - how would you suggest we minimize and control cyanobacteria in our tanks? How do you achieve this in your tanks? If we've eliminated trace elements from the discussion, then I shall return to controlling dissolved organic matter (DOM).

JPC


----------



## X3NiTH (5 Mar 2021)

I don’t add Cobalt to my mix, I have it but haven’t used it, wanted to test the BBA hypothesis that they need it for cobalamin production fuelling growth.

Haven't had long BBA growth in my tank since, it was my main bugbear, I can’t say it’s not present because some stones look like they have it but it’s not able to grow, plants that had a film of black algae are now almost clear from it, there’s an occasional leaf that still have some peripheral tufting but it is always reducing. My light is low so any algae I have is low light tolerant, the realm of BBA!

No idea how much Cobalt could be in the tank by not adding it long term and using remineralised RO/DI. I’d need an ICP test.


----------



## jaypeecee (5 Mar 2021)

X3NiTH said:


> ...wanted to test the BBA hypothesis that they need it for cobalamin production fuelling growth.


Hi @X3NiTH 

Good to be 'talking' with you again and thanks for the feedback.

Please tell me more about the BBA hypothesis. Sounds like I've missed something.



X3NiTH said:


> I’d need an ICP test.



You obviously saw the thread Cambridge tap water ICP-MS results. I'm also very interested in following up on that thread.

JPC


----------



## jaypeecee (5 Mar 2021)

dw1305 said:


> Nickel is essential for plant growth, <"they aren't sure about cobalt">.


Hi @dw1305

Would I not be right in saying that a potential problem in using the referenced paper is that "The physiological roles of Ni, Mn, and Co for plant metabolism and growth, their uptake, together with the utilization efficiency, and transport mechanisms_ for crop plants_ are fully presented and discussed in this review". [My italics]

To what extent this applies to aquatic plants we're not sure, I guess? Diana Walstad often makes reference to a limnology book by Wetzel. You don't have a copy of his book locked away in your lab, do you?

JPC


----------



## X3NiTH (5 Mar 2021)

It came out of the discussion on the causes and prevention of BBA thread (my Forum SearchFu is crap sorry) and that Vitamin B12 (Cobalamin, based upon Cobalt) may be central to it and fuels it’s growth, I tested it by not adding it and hoped plants wouldn’t suffer by it not being added (it may be present as a contaminant in another salt but it will be exceptionally low numbers). No fish food has been added to this tank in a long long while so it can’t come in that way.

I’ve been looking at ICP testing for a while since starting up a Marine tank/s for Triton Dosing possibly, thought it would be interesting to test the freshy also for long term values of elements on my regular fert dosed no water change Bucearium. I did see the thread, commented on it and it looks like an interesting affordable proposition!


----------



## jaypeecee (5 Mar 2021)

X3NiTH said:


> It came out of the discussion on the causes and prevention of BBA thread (my Forum SearchFu is crap sorry) and that Vitamin B12 (Cobalamin, based upon Cobalt) may be central to it and fuels it’s growth, I tested it by not adding it and hoped plants wouldn’t suffer by it not being added...


Hi @X3NiTH 

I tried to find the BBS thread but to no avail. It didn't appear to be in the mega BBA thread. If I understand you rightly, you used to add vitamin B12 to your tank and you had BBA problems. So, you omitted the B12 and, slowly but surely, the amount of BBA reduced. Conclusion: cobalt possibly promotes BBA growth.

JPC


----------



## X3NiTH (5 Mar 2021)

No I never added B12 (unless it came coincidentally in fish food or as the decay byproducts of lost plant tissue), I read that Rhodophyta is rich in B12 and very likely to its own benefit so I chose to prevent fuelling excess growth or even limit/prevent growth by eliminating cobalt dosing entirely. I discussed it with Burr and the others over on the PlantedTank in the ‘Custom Micro’ thread (or was it the BarrReport) asking whether Cobalt would be necessary to the Micro Mix, I decided to test it out.


----------



## jaypeecee (5 Mar 2021)

Hi @X3NiTH 

Thanks for correcting me. One of the other interesting things about Rhodophyta is their light absorption spectrum. Peak absorption occurs at 565nm (green-yellow). This extends into the blue at lower wavelengths but a lot of red light is reflected, which is why they can appear red and, hence, the name. That may, or may not be, relevant to your observations. Returning to the small matter of cobalt, you appear to have very good evidence to support the total exclusion of this trace element from your dosing regime. I assume that there has not been any downside to the omission of cobalt. This has given me the encouragement I need to continue excluding this trace element from at least one of my tanks.

JPC


----------



## John q (5 Mar 2021)

jaypeecee said:


> Hi @X3NiTH
> 
> I tried to find the BBS thread but to no avail. It didn't appear to be in the mega BBA thread.


How about the mega bba thread part 2?






						What exactly causes BBA? Part 2 - Bacterial imbalance
					

Following on from the What Exactly Causes BBA? thread, I've been reading some of the scientific literature around the subject and I'd like to make a radical proposal of an alternative cause of outbreaks of black beard algae (audouinella) in planted aquariums. I have listed some of the sources of...



					www.ukaps.org


----------



## jaypeecee (5 Mar 2021)

John q said:


> How about the mega bba thread part 2?


Hi @John q 

Thanks for the suggestion but I probably don't need that thread now. The info from @X3NiTH is the kind of information that I was looking for.

Thanks again.

JPC


----------



## X3NiTH (5 Mar 2021)

Yeah might be buried in the Mega thread.

No I haven’t seen any downsides to omitting Cobalt as yet, my Buce are without issue with regards to Micro element dosing and my Vallis snakes around on the surface water it’s so long, I suspect it’s still present in the PPB range maybe lower, though I can’t be sure without testing. Because I don’t add it and haven’t performed water change in months only RO/DI top up the only sources for its presence would be either as a contaminant in another salt or pre chelated in 
Humic Acid supplements or potentially it’s made available through sneaking through the RO/DI @ 0TDS from a background tap TDS of 35. There is Bogwood, Tropica Soil (Both Types), JBL Volcano Mineral and LECA in the tank, these may contain a potential Cobalt source, all guessing without testing!

In the tank Cobalt is most certainly not in excess, and before anyone asks I won’t change that condition just to test the premise as I won’t risk harming the equilibrium my Buce have found with their environment, I’m done watching them suffer and obliterate!


----------



## jaypeecee (5 Mar 2021)

X3NiTH said:


> ...and haven’t performed water change in months...


Hi @X3NiTH 

I've always been too afraid to say something like the above. So, I really admire your openness and honesty. Minimal water changes whilst keeping the water quality high has been my objective for quite some time. I do believe it's possible and you appear to be demonstrating that. Maintaining dissolved organic matter (DOM) at an absolute minimum using appropriate filtration media is what I want to experiment with.

JPC


----------



## Vsevolod Stakhov (12 Mar 2021)

Ni is essential for ureasa enzyme forming, so it is extremely important if you use urea as N source (e.g. Seachem Nitro). Co and Se are considered as 'useful' elements but there are no proofs currently that they are essential. WRT BBA and B12 I also had a bad experience of BBA outbreak after using of liquid fishtamins. Mineral Cobalt seems to be not so bad (at least, it has not caused any outbreaks) - I have tried 'Cobaltosan' in the past. I have found some evidence in the literature that Co activates carotinoids in plants, so that might be related to 'more red' effect. However, I no longer use Co (mainly due to my BBA fears) and I don't really see any visual difference of the red plants.


----------



## jaypeecee (30 Mar 2021)

jaypeecee said:


> I am fully aware that other factors play a part in the growth of cyano, e.g. dissolved organic matter (DOM)...


Hi Everyone,

I'm now drifting away from my thoughts about DOM contributing to the growth of Cyanobacteria. When I've gathered a few more key data, I may start a new thread related to this. If I remember!

JPC


----------



## jaypeecee (30 Mar 2021)

X3NiTH said:


> I’d need an ICP test.


Hi @X3NiTH 

I have recently sent two tank water samples off for ICP-MS.

JPC


----------



## dw1305 (1 Apr 2021)

Hi all, 


jaypeecee said:


> I have recently sent two tank water samples off for ICP-MS.


This should be interesting.

cheers Darrel


----------

