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White fungus-like dots on anubias making my fish sick

daizeUK

daizeUK

Member
Joined
18 Jun 2013
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161
Location
Berkshire
Can anybody recognise and identify these white dots on my anubias plants?

anubiasfungus_zpsz88dpkcb.jpg

004%202_zpskwvz3p0l.jpg

004_zpsrtngv2at.jpg

At first I thought they were calcium deposits or salts since I have hard water. However I have anubias in other tanks in the same water which did not show these symptoms.

I've had fish (platies) growing sick and dying in tanks which show these symptoms. I'm thinking it might be a toxic fungus or mold?

These anubias were recently removed from an old tank which I tore down because it was infested with BBA. I gave the anubias a bleach dip to kill any BBA and then put them into a 35L tank and a 120L tank. The same plants subsequently developed these hard white spots in both tanks and fish began to get sick and die.

I've found a couple of other threads on this stuff around the internet so it's not just me but nobody seems to know what it is. Here's a couple of the links I found with what looks like the same stuff.
http://www.plantedtank.net/forums/showthread.php?t=46071
http://www.plantedtank.net/forums/showthread.php?t=191401
 
That's not good, the whole plant looks sick. Could it be some sort of photosynthetically induced precipitation of something like CaCO3 ?
 
In charophytic macroalgae, use of HCO−3 in photosynthesis can be closely coupled stochiometrically to carbonate precipitation (McConnaughey, 1991):

Carbonate precipitation closely coupled to photosynthesis is also found in coralline red algae, several green algae, and numerous freshwater angiosperms developing polar leaves with high pH and carbonate precipitation being confined to the upper leaf surfaces (Raven and Hurd, 2012). Check out the link for the chemistry http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3659369/

It's only the plants you soaked that are suffering so could it possibly be something to do with the bleach increasing the polarity of the plants leaves, and maybe a synergistic interaction with the hard water, that would result in CaCO3 precipitation.

What kind of bleach was it? Calcium or sodium hypochlorite or was it hydrogen peroxide? I know it's a far fetched theory, but Calcium hypochlorite reacts with carbon dioxide to form calcium carbonate and releases dichlorine monoxide which is a strong oxidiser and chlorinating agent, maybe why your fish aren't too happy...or maybe something similar is going on.

But just spit balling, chemistry isn't my strong point, and neither is plant ecophysiology...
 
That's an interesting theory Troi! Perhaps it does have something to do with a bleach reaction. It's been three weeks since the bleach dip though. The bleach was sodium hypochlorite and was followed up with a dechlorinating bath. Other plants (e.g. crypts) were also bleach dipped and do not show the same precipitate.
 
Like I said I'm not too hot on plant ecophysiology, but each species is likely respond differently to any given scenario, so the cryps won't necessarily show the precipitate. How long after the bleach dip did the precipitate appear?
...it's the only causal link I can think of...

Edit: Pick of a leaf with a lot of the white stuff on it and drop it in to vinegar and see if it fizzes.
 
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Okay I put the leaf in vinegar and I could see tiny little bubbles rising from the affected areas.
I also dug out the kid's microscope and managed to get these pictures close up:
magnifiedScale_zpswllplbis.jpg

It looks pretty crystalline to me. Does this confirm it's just calcium carbonate?
 
I think given the above, it's more likely than not. And if so it also tells us that Anubias (at least that particular species) can synthesise its carbon from bicarbonate...which is perhaps another good reason why its a good low-energy plant particularly in hard water.
 
So it is basically limescale as I first thought and completely harmless - not a toxic fungus after all. I guess that's good news!
It also makes sense that I have only ever seen this appear in non-CO2 enriched tanks. It never appeared in the two gas injected tanks I've had and appears only very slightly in my tank with added liquid carbon. Both CO2 gas and liquid carbon seem to inhibit it.

The science journal you linked to seemed to acknowledge this kind of precipitation as a natural byproduct of photosynthesis using bicarbonates. So then I wonder why is this phenomenon not observed more often? The last time I checked I had pH of 8.3 and water hardness of around 300 mg/L CaCO3. It's very alkaline and hard but not unique so I'd expect other people to have experienced the same effect in their low-tech tanks if it were commonplace. There must be something else going on in mine to produce this much visible scale. Or perhaps it's just characteristic of this particular species of anubias petite, not all anubias.

It's sounding less realistic to me now that this scale could be related to fish sickness, despite the timing. It's a bit too much of a coincidence though. On three different occasions I've seen scale forming in my tanks (on leaves, glass and hardscape in both planted and unplanted tanks) with fish sickness and death following shortly after.
 
I've noticed that the scale forms more quickly on leaves where green algae has already taken hold. If you look at my first photo, you see that the worst affected leaf looks weak and has a layer of algae. I'd have expected the strongest leaves to develop the most scale, if this were merely a by-product of photosynthesis. Is it possible that the presence of algae somehow inhibits the leaf's ability to rid itself of precipitate, or something?
 
I think perhaps the bleach may have weakened the plant and caused the increase in polarity, hence the algae and CaCO3 respectively. Your water parameters are also pretty extreme and may have some influence of the osmoregulation of your critters...it could be a potential source of stress.
 
The fish being affected are platies though, which should be okay with these parameters.
 
Hi all,
daizeUK said:
I've noticed that the scale forms more quickly on leaves where green algae has already taken hold. If you look at my first photo, you see that the worst affected leaf looks weak and has a layer of algae.
Click to expand...
Troi said:
I think perhaps the bleach may have weakened the plant
Click to expand...
daizeUK said:
There must be something else going on in mine to produce this much visible scale. Or perhaps it's just characteristic of this particular species of anubias petite, not all anubias.
Click to expand...
I think you are both right and it relates to surface roughness of the leaves, presumably caused by either the damage from the bleach treatment, or the dead algae forming a nucleus for CaCO3 formation.

I think this one should be available to every-one <"Underwater photosynthesis of submerged plants – recent advances and methods">.

I believe that the CaCO3 "marl" that is deposited in calcareous lakes is largely precipitated by photosynthesis (often primarily of Chara spp.), and that vascular plants, like Potamogeton pectinatus and Myriophyllum spicatum, will often be encrusted with biogenic calcium carbonate as well.

cheers Darrel
 
Thanks Darrel, I came across this version of the paper I linked earlier as well - mine doesn't have the images tho...Figure 1 image B is quite telling.
Maybe the thickness of anubias leaves has a role to play as well...perhaps potential for greater polarity?
 
Hi all,
Troi said:
I came across this version of the paper I linked earlier as well - mine doesn't have the images tho...Figure 1 image B is quite telling.
Click to expand...
With apologies, you did, and I've pretty much repeated your earlier post. I knew I'd read the paper recently, but it didn't click it was from the link earlier in this thread.
Troi said:
Figure 1 image B is quite telling.
Click to expand...
I think that is approximately where we are.

cheers Darrel
 
dw1305 said:
Hi all, I think you are both right and it relates to surface roughness of the leaves, presumably caused by either the damage from the bleach treatment, or the dead algae forming a nucleus for CaCO3 formation.

I think this one should be available to every-one <"Underwater photosynthesis of submerged plants – recent advances and methods">.

I believe that the CaCO3 "marl" that is deposited in calcareous lakes is largely precipitated by photosynthesis (often primarily of Chara spp.), and that vascular plants, like Potamogeton pectinatus and Myriophyllum spicatum, will often be encrusted with biogenic calcium carbonate as well.

cheers Darrel
Click to expand...

🙂That's again an interesting read.. I notice i got a Potamogeton perfoliatus in the garden and it indeed is very beautifull and always the dirtiest plant in the pond. The looks are somewhat simular but i got soft water and it's just dust in the flow it catches and accumulates, i thought. When i feel the leaves it indeed feels like soft sandpaper.. 🙂

difficult to take a picture from above the water surface in the sun.. Couldn't get it any clearer, but if you know what you're looking for you'll see it.
WTl3Wly.jpg
Looks simular.. 🙂
 
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Many thanks for all the help solving the mystery of the white dots, the information has been very interesting and I really appreciate it.

I'm still somewhat bemused by the fish lethargy and deaths that seem to go hand in hand with this apparently benign scale. I deliberately chose platies as a fish that would cope well with my water parameters so I find it odd that they would succumb before other fish and invertebrates. For now I think I'll have to accept that the plant and fish symptoms are probably unrelated and coincidental.
 
Yes but it kinda doesn't realy feel like debris, than you rather would expect it to feel slimey, the clean leaves feel smooth and the dirty leaves kinda grainy.. Actualy never realy noticed it and didn't put much attention to it till this topic came up. It's like catching debries and using that material as a accumulation host as carbon deposite. Like an oyster does with a grain of sand and making a pearl of it... Ithink i'm going to take a measure for gh and KH again, this your a threw some Ardenne Rocks in there, they are know to camtain loads of calcium. 🙂 It might not be as soft anymore as i thought..
 
daizeUK said:
The fish being affected are platies though, which should be okay with these parameters.
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Yep you've got a point...Palties were the first tropical fish I kept as a kid and they're pretty unfussy. What other fish/critters do you have in the tanks and do they exhibit any symptoms?
 
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