Cories Died

[Pixie25]

ive had my tank set up for about 2 1/2 months now. its a 27.5 gallon community tank, with some real plants, bogwood and sand substrate. i keep tetras, rasboras, shrimp and cherry barbs in it as well as cories. up till now the tank has stayed in a good condition and most of the plants i have, have grown.

ive not had any casualties in the tank really apart from the cories. one died a few weeks after we got the tank set up and one just died the other day. it got me wondering what could be killing them off. there is one thing that the cories dont have in common with the other fish and that is that they are in contact with the sand almost constantly.

on closer inspection i actually have several types of agae in my tank. green spot, red beard algae and there is also a thin layer of greyish algae that develops on the surface of the sand. i disrupt this layer weekly during water changes. the sand is about 2 1/2 inches deep at the back and i peeled some of the backing paper off yesterday to look at the sand more closely and it is dark greyish about an inch deep into the sand.

so what is this stuff and how do i get rid of it/control it? i really would like this tank to stay pleasing to look at and be successful for the fish. do i need to disrupt the sand to stop the algae building up or do i just leave it there?

please help me, because i really hope that if it is something to do with the sand that the other fish in my tank wont begin to suffer too. i would also like to replace my cories but i wont if they are just going to die again...

 

[WILDER]

Right we need to no size of tank in gallons or litres, plus full fish stock how many and which kind, water stats in ammonia,nitrite,nitrate,and ph, maintanace routine, and corys are not cycling fish, and they are very prone to bacterial infections, also what do you feed the fish.

 

[jimbooo]

my guess is BGA. blue green algae

it grows on the substrate in green sheets. kind of like a thin film of jelly but it is green as grass and obvious. you say your sand based algae is grey so that doesn't add up. grey algae is dead algae.

if you do have BGA in the tank that is the cause. it's not actually algae, more of a bacterial colony and is highly toxic to fish. i have lost corys to this in the past as they like to eat it for some reason.

if you cant see a green film anywhere ignore this reply though. i dont want you to panic. it really is very obvious to see if present

 

[Inchworm]

Hi Pixie25

Before you do anything else, I suggest you start a thread in the Planted Tank section to describe this condition and to ask if this is indeed an algae. If so, they can help you resolve it.

Since they live at the bottom, corys are quite susceptible to bacterial infections if dirt and/or uneaten food accumulate there. But, while the corys might be the first fish to be effected, their problem could spread to the other fish as well. While waiting for a final diagnosis of the problem, I suggest that you vacuum the bottom as often as necessary to remove that layer that is forming.

What kind of filtration do you have? What are you feeding your fish? Have you ever watched to be sure that it's all being eaten?

 

[Pixie25]

i already listed what i have in my tank and the size, a full list is in my profile (-1 cory)

i have an external fluval 205 and do weekly 25% changes with a gravel vac. the greenish grey shows up in splotches because my sand is light in colour. and little black bits of debris seem to collect throughout the week, but all get sucked up when i do my changes.

i feed one pinch of flakes (for the rasboras) one pinch of tetra prima pellets (for the tetras and barbs) and one pinch of catfish pellets one time a day. to be honest the food doesnt even have time to touch the floor when i feed them!

once a week i dont feed any dried food and just feed about half a cube of frozen brine shimp. thats the only thing that doesnt get eaten all at once, but i make sure it is all gone within an hour or so.

i will do water tests in a while and post the stats if that will help.

 

[WILDER]

The corys did you use them to cycle the tank?

 

[Pixie25]

nope i used the barbs to cycle it. but i added the cories as soon as the levels were all normal.

tanks stats just done and are as follows:
ammonia 0/0.25 (the yellow never looks as bright as on the chart)
nitrite 0
nitrate 10
PH 7.4

oh and i forgot to mention my tank got white spot a few weeks ago (maybe a month ago) and i treated the tank and didnt lose any fish to it.

 

[WILDER]

Right the corys do they look pale in clour or darker in colour, do they look bloated, also what do there barbels look like.

 

[Pixie25]

ive only got 1 cory left now and he is fairly pale apart from his peppery marks all over him.

both cories that died lost all their energy before they died and sort of layed on their side on the bottom of the tank. every time i thought he was dead but when i tried to net him he would swim off (using all of his tiny little bodies energy). i didnt have the heart to flush him when he was still alive so he was like this for about a day.

 

[WILDER]

More than likely it will be a bacterial infection, i would medicate with a bacteria med, can you issolate the cory.

 

[Pixie25]

dont have a quarantine tank at the moment. i made it into a betta tank.

if it is a bacterial infection will any other fish be affected? what are the signs?

 

[WILDER]

No they might be ok, corys seem to pick them up easily, sysmtoms there are loads from ulcers,dropsy,swim bladder, finrot, sluggish behaviour, laboured breathing,bumps, darkening in colour, that just a few.

http/www.petsforum.com/cis-fishnet/afm/G29060.htm

 

[Pixie25]

the first one that died a while ago now, seemed to not be able to stay on the bottom of the tank. i thought he must have damaged his tail or something.

the one that died the other day didnt have this though. theres really nothing abnormal that ive noticed apart from the sudden flourish of algae. i hate algae.

i just woke up one day turned the aquarium light on and the cories was on his side looking dead. poor little mite.

 

[WILDER]

Do you mean he couldn't maintain his balance he was tipping upside down.

 

[Pixie25]

he didnt tip upside down - just every time he stopped swimming he would begin to float up from the sand. nearer his death both cories layed on their side all day long on the bottom of the tank.