Corydoras smacking side to ground, healthy?

[MaxPowers]

I was wondering: when a corydoras smacks his side to the ground (very fast), is that a sign of happiness or discomfort (itch?), does not happen very often,

they're pretty happy though, 2 of them are definitely a couple, always swimming with and touching each other,

I've got 2 corydoras who's barbels are gone... I've read about it, it means too much nitrate or too rough soil or bacteria...
(the fact is, as I reinstalled the aquarium, I didn't do anything with it, the soil grew over with algae that turned grey after a while, so I removed that dirt and cleaned it up, the plants in the pics survived, so I thought it would be ok for fish again... but you probably can't get rid of bacteria...)

here you can see the soil I used:

I think it wasn't meant as top-layer, but I liked its color, it's very light and hollow (I think), cause 30% of it floated, but mostly rounded (only some broken peaces of it could be sharp...)

I have two of these corydoras which both have lost there barbels:

my other bronze corydoras did not have any problems for a much longer time...

but now my other corydoras (the normal bronze colored) are getting also thinner barbels (at least the smaller one), so I changed the soil to that you can see in the upper images of the corydoras (it's cold caviar: very small, like 1mm and round, though I dislike its color...)

I have 7 corydoras (even another species), 2 gibbiceps and 2 beta's (male and a female) in a 45 liter tank

I've even used 'Easy-Life Crystal' to make the refresh water fish friendly, today as I cleaned and placed the new caviar soil I've use 'TetraAqua EasyBalance' (uses Nitrate Reduction Granules, reduces phosphate, has vitamins etc)

I told the tropical fish store about it, she said she never heard of anything like that... gotten only bad or no info (I asked her before I bought them, about the soil type etc)... tsss, they's shouldn't be allowed to sell animals...
sold me recently a Beaufortia leveretti (the store called it 'Liberty', a pleco like shaped like a manta, cool fish, super fast), it was very small, died the next day (I asked whether as strong as a pleco... special needs etc, guess not... anyone experience with that fish? maybe I had bad luck and it had a heart attack or something unnatural...

any info more than welcome!

Regards *PEACE!*

 

[Fuzz16]

it is possible that it might be the water thats bothering them.
check your parameters.
and your corys will outgrow that tank and your male betta will end up killing the female if left together after they spawn.

and actually ive seen this pleco called a butterfly pleco. they get about 12cm though and would have outgrown that tank i believe. sorry about loosing him

but get your water checked, keep a close eye on the corys. hopefully thier just being weird.

 

[IDunnoWhy]

The fish "smacking" his/her side to the ground, if I'm not mistaken is called "flashing" (My fish will do it from time to time, sometimes on the substrate, sometimes on a rock or whatever), I do believe they are itching themselves when they do this However if it's a constant thing, than thats a sign of trouble, fungas, ich etc. possibly even bad water quality, but I'm not sure on that one.

As far as the missing barbels....Hmmm I've got 1 single albino cory (I know, I know, they're suppose to be in groups of 3 or more), he's in a tank with "medium to small" gravel sizes, he digs like a miner, and still has his barbels with no problems, so I'm not sure why yours are missing theirs, Hopefully someone else will chime in on that topic for ya'

 

[MaxPowers]

my tank is 60x30X30 cm, so technically maximum water content is 54 liter,

in my tropical aquarium fish book it says cory's can be held in smaller or bigger fishtanks, as long as there are sufficient plants and the water level isn't too high (because the inhale air at surface that they can take up through there intestins)

betta's no problem, the temperature is normally around 25°C, when I would increase temperature he'll go nuts ;-) and make his nest, but female has enough hiding places (wood, plants) and is fast enough,
I used to have the opposite problem: vicious females attacking the MALE !
very frustrating... long beautiful fins reduced to fishfood... (don't remember this happening when I bought them in other store some years ago... weird), but now I've got a good female

the only fish that will outgrow the tank are the Pterygoplichthys gibbiceps, which can reach up to 20cm in an aquarium, and they grow fast... bought the first 3-4 months ago, the second 2 weeks ago, and now my old one looks huge compared to the new one, but I will sell it to tropical fish store and buy smaller one when he's too big, also, in literature I read they like company from each other, but maybe because the difference in size, cause they're not social to each other at all, the bigger gibbiceps pushes corys and smaller one kind of like a hoovercraft away ;-) that is when I throw in food

could be my info is incorrect...

 

[MaxPowers]

here's a video of that behaviour:

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I've seen the bronze do that much faster and harder against gravel... but I tend to associate it with happy mood... might be wrong though...