Hello all,
I have 4 bronze corys in a sandy planted tank, and have found that 2 of them have now lost one or both pectoral fins. Just little stubs. No fungus growth or anything.
Why have they lost them? Could it be because they banged into some rocks in the tank?
- Seweryn
Corys losing fins
I've had the tank set up for 3 months.
It's a 130L, pH 6.7-7.2, CO2 8-20ppm, 0 ammonia, 0 nitrite, 60ppm kH, 90-100 ppm gH.
2 30W lights, but plenty of vegitative cover, and several caves.
Fine gravel/sand bottom, 2 pieces of driftwood and pieces of slate-like sedimentary rock (inert according to my tests w/ acid and guppies)
Other fish are 2 baby bristlenoses, neons and 2 juvenile Apisto cacatoides (pair).
They seem comfertable, as they have spawned once, putting down paird clumps of eggs, but about 2 weeks ago, one of them got hemmoraged sides (mostly on hte belly) and promptly died. But by then some already have had fins missing. All the other fish were fine.
It's a 130L, pH 6.7-7.2, CO2 8-20ppm, 0 ammonia, 0 nitrite, 60ppm kH, 90-100 ppm gH.
2 30W lights, but plenty of vegitative cover, and several caves.
Fine gravel/sand bottom, 2 pieces of driftwood and pieces of slate-like sedimentary rock (inert according to my tests w/ acid and guppies)
Other fish are 2 baby bristlenoses, neons and 2 juvenile Apisto cacatoides (pair).
They seem comfertable, as they have spawned once, putting down paird clumps of eggs, but about 2 weeks ago, one of them got hemmoraged sides (mostly on hte belly) and promptly died. But by then some already have had fins missing. All the other fish were fine.
Your water perameters look fine and you test the water quite regular i assume. So more questions have the corys ever been exposed to nitrite or ammonia during the cycle period of your tank, or are they new arivals? Are you familiar with the pit falls of co2 dosing and have checked your pH doesnt fluctuate too much during the night. test before the lights come on and then test again middle of the day, and make sure there is not too much movement you can expect .2 or .3 of a degree. or are you aware of any previous pH crashes as the after effects can last.
wow im having exactly the same prob right now with my albino, but only a couple out of the school. one of the little fellas dorsal fin has been slowly dissapearing and i cant figure out why. they also seem to flash about a bit and im not sure why that is either. it would be a sure sign of bad water but i do tests and water changes every 3 days. ph 6.8-7.0 ammonia 0, nitrite 0, nitrate 3-5ppm. lots of plants, caves, light, food. every other fish is fine and not all of the cories are having this problem, only 2 of the 5. seweryn has the same setup as me down to the apisto pair... what could be the proble? what is the co2 pitfalls mentioned above as i use a pressurized tank setup to insure happy lotus plants. i guess there could be a ph spike occuring when i do a water change as my tap water is about 7.8 and the co2 runs it down to itsw 6.8-7.0. are cories that ph sensitive? more than a dwarf cichlid? i read the cories were pretty hardy and could handle a wide range of tank conditions. all of there barbels look great which ive read are a good health indicator.
The pit falls of co2 dosing are that a you could over dose depending on your kH and to a lesser extent GH readings, this effect causes the ph to swing quite alot and effects almost all fish though. have you a co2 test kit? or you could be depriving fish of oxygen if at night there is a lot of surface cover then gas exchanges can not take place, hand the pH might be crashing. do you both use night time shut off valves? corys can lose there fins for a number of reasons, i.e too acidic for some species, aggression from other species (however two young apistos are not much to worry about in 130l unless they are trying too breed and even aggression then from this species is rare) and finaly nitrite can also cause this condition. are you sure there is no disease? corys are quite hardy but dwarf cichlids in my experience do not mind low ph i.e below 6 however corys do like high oxygen and stable pH.
please give as much info as possible. How long after you aquired the corys in question did you notice the effects? are the fins growing back? have you returned to the shop to see if they have the same problem? And anythink else you can think of. obviously you have made sure they are not forceing there way into small gaps to find food?
please give as much info as possible. How long after you aquired the corys in question did you notice the effects? are the fins growing back? have you returned to the shop to see if they have the same problem? And anythink else you can think of. obviously you have made sure they are not forceing there way into small gaps to find food?
i think the fact that my ph may be fluctuate to much for the comfort of the cories may be very probable. my kh is around 3 and my ph is normally around 6.8, so that puts the co2 around 14ppm. i dont have a test kit i just use a chart thats posted around the net. the problem i have is the co2 going into the tank does fluctuate as the tank of gas runs low. pressure drops, i crank it up and try to even it out...etc. i check the ph and see its still around 7.0 so ive never considered the possible detriments of a ph swing, but now that i know lll keep an eye on it.
ive had the cories about amonth and noticed it about 2 weeks aftert i got em. its only happening to 2 of the school of 5. the oxygen should be at a good level as ive got a jungle going on in the tank, the airator on the HOB going, and the co2 is only at 14ppm. i guess they could be working themselves in little spots under the driftwood where the khulis hang out, ill try to dig the rocks out a bit for some more room. im keeping an eye on em alot so i guess ill see if they improve or if more fin issues arise. thanks for all the help.
ive had the cories about amonth and noticed it about 2 weeks aftert i got em. its only happening to 2 of the school of 5. the oxygen should be at a good level as ive got a jungle going on in the tank, the airator on the HOB going, and the co2 is only at 14ppm. i guess they could be working themselves in little spots under the driftwood where the khulis hang out, ill try to dig the rocks out a bit for some more room. im keeping an eye on em alot so i guess ill see if they improve or if more fin issues arise. thanks for all the help.
I'll try to monitor my pH and CO2 levels at night, in the morning and in the afternoon, but I am sure they get enough O2 at night as I drop in an airstone for the night.
I noticed the missing fins about 3 weeks after I introduced them, but the tank had been cycling for about 3 weeks before I put them in. They were the first fish in as well for the first week.
I noticed the missing fins about 3 weeks after I introduced them, but the tank had been cycling for about 3 weeks before I put them in. They were the first fish in as well for the first week.
Can both of you reply with the results with your ph movement and the recovery(hopefully) time of the corys fins. I have often wondered if there is enough instructions given within the instructions of co2 units.
Seweryn it is a good idea to put an airstone in at night however the drawback will be very quick disbursing of the co2 and hence a pH increase.
Tricks not in the books:
put the co2 timer to come on between 1 hour and 30 minutes before the lights come on depending on bubbles per second. How many BPS or you both running? this makes sure the tank is well saturated with co2 so when the lights come on photosynthesis can start quicker.
Remember the amout of mg/l you use will depend on how powerful your lights are the amout of light is the most powerful overriding factor. what this means is if your only running 30-40 watts then the plants may only be using 5mg/l which means most is going to waste. this rule also applys to plant foods no point in overdosing because it simply wont be used.
Make the co2 unit turn off 1 hour before the lights turn off in this way the plants can use up some of the co2 already in solution.
At night use a very small power head or other small pump on a timer just to move the water surface around and disburse the co2 in this fashion, this method i have found doesn't cause a pH increase.
Seweryn it is a good idea to put an airstone in at night however the drawback will be very quick disbursing of the co2 and hence a pH increase.
Tricks not in the books:
put the co2 timer to come on between 1 hour and 30 minutes before the lights come on depending on bubbles per second. How many BPS or you both running? this makes sure the tank is well saturated with co2 so when the lights come on photosynthesis can start quicker.
Remember the amout of mg/l you use will depend on how powerful your lights are the amout of light is the most powerful overriding factor. what this means is if your only running 30-40 watts then the plants may only be using 5mg/l which means most is going to waste. this rule also applys to plant foods no point in overdosing because it simply wont be used.
Make the co2 unit turn off 1 hour before the lights turn off in this way the plants can use up some of the co2 already in solution.
At night use a very small power head or other small pump on a timer just to move the water surface around and disburse the co2 in this fashion, this method i have found doesn't cause a pH increase.
Unfortunately, I do not have a bubble counter, as I just have a little DIY yeast setup, which is injected into the outtake hose of my eheim. But I would estimate about 1 bubble per two seconds. I usually leave the CO2 running all night and just plop in the airstone. Unfortunately, the CO2 is the only thing that will drop my pH down to ~7. I'll try to get better readings between all of the photoperiods. I've got 60W from 2 fluoros, so I would say that is a medium amount of light...
-S
-S
so i thought id write in with an update on how my 2 cories are fairing. theyre not, they died. but i do believe i figured out what played at least a part in their deaths. ich
a couple days after last writing on of my otos developed ich. i believe this could has also been effecting the cories. that would explain the flashing, and would explain fin damage due to flashing.
so i dosed an ich treatment a i weakened dosage and although the visable spots on the oto has vanished, the 2 cories died. the other 3 which had no fin issues are fine, they didnt really care for the ich treatment though but after i cleared out the meds the returned to normal. ill keep an eye on them all for signs of the parasite returning.
a couple days after last writing on of my otos developed ich. i believe this could has also been effecting the cories. that would explain the flashing, and would explain fin damage due to flashing.
so i dosed an ich treatment a i weakened dosage and although the visable spots on the oto has vanished, the 2 cories died. the other 3 which had no fin issues are fine, they didnt really care for the ich treatment though but after i cleared out the meds the returned to normal. ill keep an eye on them all for signs of the parasite returning.
Sorry to hear about your cats Bean.
Also an update for myself.
My two corys which had fins missing (one both pecs, and the other one only it's left one)
are doing well, and look like are growing back their pec fins, alabeit slowly.
I did pH testing, and my normal daytime pH level is around 6.6.
If I put in an airstone overnight, it raises it up to 6.8 or 7.1 (2 different days)
If I just turn off the CO2 at night, the pH raises up to 7.0.
So it does not look like the airstone does much difference in terms of pH when compared to turning the CO2 off, but is a pH swing of 0.5 every night too much for thecorys and other fish (dwarf cichlids, neons, etc...)
-Seweryn
Also an update for myself.
My two corys which had fins missing (one both pecs, and the other one only it's left one)
are doing well, and look like are growing back their pec fins, alabeit slowly.
I did pH testing, and my normal daytime pH level is around 6.6.
If I put in an airstone overnight, it raises it up to 6.8 or 7.1 (2 different days)
If I just turn off the CO2 at night, the pH raises up to 7.0.
So it does not look like the airstone does much difference in terms of pH when compared to turning the CO2 off, but is a pH swing of 0.5 every night too much for thecorys and other fish (dwarf cichlids, neons, etc...)
-Seweryn
Seweryn you kh as i remember was about 5-6 which would make your tank quite well ballanced (hence the lack of movement showed on your tests) and that amount of movement would be considered within normal range, so your corys should be ok. Is it possible that the tank base is dirty agrivating the corys and just needs a good clean.
It's reasonably clean, with both the corys and some riffle shrimp doing cleaning duties, but my two small bristlenoses do crank out a bit of poo. I'll give the surface a good vaccuming this weekend.
The only other possibility that I can think of is my flat rocks (which I have put bits in the sand at angles for aesthetics). Some of them do have sharp edges, and maybe the corys run into the edges when I walk into the room and they skitter around, or when they are in spawning mode.
-S
The only other possibility that I can think of is my flat rocks (which I have put bits in the sand at angles for aesthetics). Some of them do have sharp edges, and maybe the corys run into the edges when I walk into the room and they skitter around, or when they are in spawning mode.
-S