Cory sterbai barbel problem

[harold]

Hello,



I cannot deduce why my cory's barbels are keep getting shorter and shorter. There is a total of 8 Sterbai cory (5 adult, 3 juvenile) in my 90G tank. Apart from the short barbel, they seem to be otherwise healthy. They seem to have a bit problem locating where the food is, probably due to the barbel loss, but they found the food eventually. Most of the time, they will chill under a driftwood in the back of my tank, or on the leaves of my anubis, but they will swim around at feeding time. They seem to be afraid of people walking pass though, and would swim back to hiding whenever there are people walking pass.

Here's more photo of my Cory (Sorry for the quality. It's really hard to take a good picture when they just swim off whenever I appear).






This is the juvenile with the most serious barbel decay. The side of the mouth is white, and the barbel is reduced to a bud. I have read about fungal and bacterial infection in other barbel erosion posts, but unlike them, there is no sign of cotton growth or red stripe, and I don't know what exactly is causing this.

All the other adult's barbel seem to be quite a bit shorter comparing to 3 months ago when I purchased them. The 3 juvenile have really short barbel at the first place, but at the time I thought that was because they were young. It doesn't seem to be the case though when I saw photos of young cory with full barbels.

I have already looked at the FAQ section, and other threads about barbel erosion, but they don't seem to be related to my situation. I am using a very fine sand for substrate. I can pinch a bit with my finger and rub against it without hurting myself, so the sand should be smooth enough. With Nitrate at 20, I think the water is rather clean as well. The FAQ section also mentions substrate depth. If that is the case, how shallow it has to be? 1.5 inch is already the min. depth I needed for my plant.



1. Water parameters
a) Temperature range: 26-27°C
b) pH 6.5
c) GH 4-5
d) KH 4-5
e) Ammonia 0, Nitrite 0, Nitrate 20
f) Water change frequency 50% a week


2. Tank set up
a) Size: 120cmx45cmx60cm 90g tank
b) Substrate: sand with an average depth of 1.5 inch
c) Filtration: Eheim 2217 x2
d) Furnishings: medium planted, with driftwood and rocks
e) Other tank mates: Congo tetra x10, Emperor tetra x14, lemon tetra x1, Bristlenose Pleco x5, Siamese Algae Eaters x3, Amano Shrimp x14, Sterbai Cory x8
f) How long has it been set-up? 5 months
g) Food used and frequency: A mix of Tetra Bits complete, NLS Thera A, Hikari Sinking Wafer for catfish, and Hikari Algae wafer (mainly for the pleco, but somehow the cory likes it more than any other meaty food)

[bekateen]

Hi Harold,

Sorry to learn about your struggles with the sterbai. As far as I know, there are very few (or no?) causes of barbel loss beyond sand issues, water quality and infection. So my thought is this - even though everything looks good, something is off, perhaps in your case a combination of water quality and infection. Also, depending on the depth of your sand, you might have toxic gases built up.

My first suggestion is to up your water changes from 50% to 80%, stir your sand to expel gases as you drain the tank, and treat the tank with Melafix.

Try that for a week and see if it makes a difference. The barbels won't be back to normal, but I'd hope the erosion had stopped and the white areas were shrinking.

Good luck, Eric

[CoryfanAad]

What exact type of sand is it?
One of the corys seem or have greyish spots on the head as well.
Is there a good waterflow ?

[harold]

Hi Harold,

Sorry to learn about your struggles with the sterbai. As far as I know, there are very few (or no?) causes of barbel loss beyond sand issues, water quality and infection. So my thought is this - even though everything looks good, something is off, perhaps in your case a combination of water quality and infection. Also, depending on the depth of your sand, you might have toxic gases built up.

My first suggestion is to up your water changes from 50% to 80%, stir your sand to expel gases as you drain the tank, and treat the tank with Melafix.

Try that for a week and see if it makes a difference. The barbels won't be back to normal, but I'd hope the erosion had stopped and the white areas were shrinking.

Good luck, Eric

Thank you for your advice.

I vacuum my substrate every time I do WC, and use a stick to stir the substrate in areas with plant, but I guess it can be further improved. Will increase the water change to 40% per 3 days to see if it improves. I have also added freeze dried Australian blackworm as an extra protein source to promote regrowth.

Speaking of melafix. It would be rather expensive to medicate the whole tank, and when I was searching on web, I found a home made melafix recipe of 1% normal tea tree oil and 99% water. It seems that the tree oil has similar effect to the active ingredients of melafix, but only much cheaper. Have anyone used this before? Would want to hear some first hand experience before trying.

[harold]

What exact type of sand is it?
One of the corys seem or have greyish spots on the head as well.
Is there a good waterflow ?

I am not 100% sure, since it is not stated on the package, but I think it is a kind of garnet sand. This sand is widely used by cories, plecos, and eartheater keepers in my area, and they have not reported similar problems.

As for the flow, currently the only sources of flows are the two spraybars and the air pump, as seen in the picture above. Most plants seem to be moving gently in the current. There is one dead spot at the right hand corner, but I vacuum that area throughly every time I do wc. Still, I will add one more circulation pump tomorrow to try to eliminate that dead spot.

About that grey spot, my guess is that the cory has bumped into something. It doesn't seem to be infected in any way.

[pleco_breeder]

Didn't see this mentioned anywhere in the post, but there is an obvious bacterial infection. The third pic in the post, single cory sitting on sand facing the camera, shows the start of obvious bacterial ulcers. Most likely, the same infection is causing the deterioration.

[harold]

Didn't see this mentioned anywhere in the post, but there is an obvious bacterial infection. The third pic in the post, single cory sitting on sand facing the camera, shows the start of obvious bacterial ulcers. Most likely, the same infection is causing the deterioration.

I see. So that grey mark is a bacterial infection as well. Thanks for telling me. That cory seems to be eating readily for now. I will see if the melafix treatment work. If not, I will switch to myxazin after the melafix treatment ends.

[Fundulopanchax76]

I remember i saw in the past that planaria worms, if they are a lot could attack and eat corrys barbels. If you feed the fish with tubifex you could infect your tank with planarias, because planarias kill and eat tubifex too and live in their colonies. Try to observe your tank in the night for planarias on its glasses. You will see them if you suddenly turn your lights on.

[AZCatfish]

Harold - look at that sand under some type of magnification like a Jewelers loop. Make sure it isn't sharp. I don't use sand so I'm not an expert, but aren't you suppose to keep the depth to about a quarter inch so it doesn't go anoxic? It looks pretty deep in your tank. Then when you stir it up during water changes you may be releasing toxins and bacteria into the water. Stirring it up may be causing more harm then good. Perhaps a sand expert can chime in here.

[AZCatfish]

Harold - Here is another idea for you to consider. My tank use to have all coarse pea gravel so I could grow plants. The corys did fine but I kept reading about how sand is best. So I set up a "cory beach" area for them in the front center of the tank using Carib Sea Peace River Gravel. It was the best thing I ever did. The cory's were on it right away digging and playing. I have 10 sterbai and its their favorite area. I have a strong bottom current in my tank so I can't use true sand, but the carib sea is pretty small. The bigger corys can expel it from their gills and the littlest ones don't have a problem digging in it and pushing it around.

I wholehearted recommend setting up a "cory beach" area in a tank that doesn't run sand. Here is a pic.

What I am trying to tell you is that you don't have to use all sand. You can use a deeper coarse gravel bed for your plants and have a thin sand beach area for the cory's. And the corys will like the variety, because that is what is closer to nature.

[harold]

Just another update. So, after 5 days of melafix treatment, the grey marks on the cory have disappeared. The barbels look pretty much the same, but I guess it will take a lot more time. Would maintain the WC schedule and wait for signs of improvement. I have also noticed an increase in activity after I added the powerhead. I suppose the cories appreciate the increase of flow.

In the meantime, the cories have just spawned in the tank. I have managed to find 9 of them and transferred them to a breeder box hanging on my 10g tank. I also added an airstone beside them.

[harold]

I remember i saw in the past that planaria worms, if they are a lot could attack and eat corrys barbels. If you feed the fish with tubifex you could infect your tank with planarias, because planarias kill and eat tubifex too and live in their colonies. Try to observe your tank in the night for planarias on its glasses. You will see them if you suddenly turn your lights on.

Thanks. I can't find any. I doubt I would introduce any of them from food, as I have only ever fed freeze dried worms, pellets and wafer.

[harold]

Harold - look at that sand under some type of magnification like a Jewelers loop. Make sure it isn't sharp. I don't use sand so I'm not an expert, but aren't you suppose to keep the depth to about a quarter inch so it doesn't go anoxic? It looks pretty deep in your tank. Then when you stir it up during water changes you may be releasing toxins and bacteria into the water. Stirring it up may be causing more harm then good. Perhaps a sand expert can chime in here.

hmm, I thought the roots of plants will keep the sand aerated. And I regularly use a stick to stir the substrate to prevent any aerobic spot from building. Not sure if that is enough though.

[dw1305]

Hi all,

[hmm, I thought the roots of plants will keep the sand aerated. And I regularly use a stick to stir the substrate to prevent any aerobic spot from building.

It depends a little bit on the plants, but plants like Amazon Swords (Echinodorus spp), Vallisneria and Cryptocoryne spp. are pretty efficient at transferring oxygen to their root zone, and roots are leaky structures.

You will always have areas in the substrate that are de-oxygenated, it isn't a problem and it is what happens in nature in most scenarios. It is in the substrate, in zones of fluctuating REDOX values, where many plant nutrients become available.

You can just carry on with the syphoning from just above the sands surface, you don't need to stir up the sand.

I like a sponge pre-filter on the filter intake, it keeps sand and dead plant material etc out of the filter.

cheers Darrel