Cory's and aquarium salt

ftbetta

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Hey All,

Question about my cory's and aquarium salt.
Background info:
10G tank with a handful of corys. I do regular water changes and have had a very stable tank with the same fish in it for years. It has play-sand as a substrate and they eat hikari sinking wafers (the orange bag). Sorry this is a lot of details, but I just tried to cover all the bases

*About a week ago (I'll call this day one): I noticed that one of my corys was acting a little bit odd, and was swimming up the walls a bit, not to the surface, about halfway, and would go back down and act normal, nothing looked visually wrong, but that's not normal behavior for any of them. Not knowing what was up, and not having anything else to go off of visually, and all ammonia and nitrates and nitrites were at zero, but I went ahead and did about a 50% water change (normally I do about 20% every 10ish days). Then it had been a little bit since I had done like a deep tank cleaning, so thought maybe something weird was building up and maybe that would help. IWiped the algae off the walls (normal build up, nothing big or gross), I also have algae that builds up under the sand right against the glass that I don't regularly clean, but I stirred up the sand and just wiped it off the glass with my finger. Then with all that floating around, I scooped out about half the water into my designated fish tank bucket. Took all the plants (one plastic, others silk and silicone - nothing has been added in ages though) and rocks and stuff, I have a designated fish tank toothbrush and I put each item into the bucket of removed water and brushed off the algae or grime or whatever it is that eventually builds up on things in there. Then placed them back in the tank. Pulled out the filter pad, put it in the bucket and brushed off some gunk, but it was still pretty icky and kinda clogged, so I ran reverse water through it from the sink (I know it has chlorine and kills a bunch of the good bacteria that lives in there. I try not to do this, but the jet of water from the sprayer really washes a bunch of gook out, and it needed it this time). Then I put everything back in, added fresh water with de-chlorinator, and let it be. The water was a bit cloudy at that point, nothing major, but it cleared out by morning. I left the water level in the tank a little bit lower so the water from the filter splashes because I thought if he was swimming up for air, maybe that would help put in a little extra oxygen in the water. BUT the fish was still acting weird.

**Day 2 and 3: I tried to just let everything be, thought maybe the removing and replacing of plants had actually stressed them out, and so thought that might be why he wasn't recovering, and so just try to let everything be for a few days. No real changes either way as far as the fish. I kept checking on him, visually absolutely nothing wrong, he was still eating and acting normal, other than these trips up the wall (but still not to the surface at all)

**Day 4: did a regular water change amount ~2 gallons out of the 10G tank. I was thinking here that just about every other time I've had issues it's been something building up in the water, and doing an increased amount of water changes has mostly solved all of them. Fish still swimming up the walls. Still nothing visual. After watching for a little bit I noticed that where as acting normally about 90% of the time, sometimes when he would move around on the bottom, instead of kinda swimming/walking/snuffing through the sand as they move, he would like swim, get an inch or so off the bottom, and sometimes kinda tilt as he was doing this, but always landed back right side up. At this point I was very skeptical that he was just going to "get better" and in hindsight probably should have started problem solving at a higher level by at least this point.

**Day 5: Came down in the morning and he was resting on his side at the bottom, but when he moved, he righted himself, and would swim normally, but a few times throughout the day I kept catching him sideways, and in the afternoon not only was he swimming all the way to the surface, but was now spiraling as he swim up and down. I did another regular water change because I was really doubting my decision to stir things up in the tank a few days ago, and the only think I could think of was there had been some bacteria or residue on something that I had mixed up, and that by doing water changes it would help get rid of it. I also went to the local pet store and had them test the water because I thought maybe my strips were old or something. She said everything was zero and pH looked just fine (I didn't ask her what the value was though). I told her about the fish and she recommended aquarium salt, because it helps their gills absorb more of the oxygen and stuff in the water and can be good for other water issues as well. It said to add 1 slightly heaping tablespoon for every 5G. I added that a few hours ago, and the fish is acting the same and continues to decline in swimming ability. Only now I can see that his gills on one side are noticeably pink. (and through all of this the other fish seem just fine btw)

Reading here and various places online it seems like there are varying concentrations of salt you can add for different things. Should I add some more? are cory's particularly sensitive to salt? That's all that's all that's in the tank species wise.

At this point with the spiral swimming and such is there anything to be done? or is it kinda like just let him be and scoop him out later?

Thanks guys in advance
 
I don't know much about salt because cories do tend to be sensitive to it so I don't use it. @Colin_T is knowledgable about the use of salt.

It could be that something weakened the cory's immune system and he developed an opportunistic infection from bacteria that is present in the water all the time but only causes illness in stressed fish. If it were me I would try treating him with an antibiotic in a separate tank (or even a plastic storage bin if you have no extra tank) as a last resort. I can't tell if you live in an area where antibiotics are available over the counter in pet stores or online.

You would only be able to guess as to the causative organism but using an antibiotic effective for gram negative bacteria would be a reasonable choice since the fish has not shown any sign of external infection. Kanamycin (Seachem Kanaplex) would have good gram negative coverage and would be absorbed into the fish's body to treat an internal infection.

It might not be an infection or you might end up picking the wrong antibiotic but if water changes and salt have not improved the situation trying an antibiotic is pretty much the last thing you could try that I know of.
 
Any pictures and video of fish swimming in spirals?

Normally when fish start spinning through the water, they have an internal infection in the brain. It is usually protozoan based, although it can also be bacterial or viral, but normally it's protozoan. This is caused by over crowded tanks, dirty tanks, dirty filters, or lack of water changes, and there is no cure.

You can try salt. Use 2 heaped tablespoons of rock salt per 20 litres of water. Keep salt in tank for 2-4 weeks. The salt normally stops the disease from spreading to other fishes but the sick ones are usually too far gone.
 
FULL INSTRUCTIONS FOR USING SALT IN FRESHWATER AQUARIUMS

For some fish diseases you can use salt (sodium chloride) to treat the ailment rather than using a chemical based medication. Salt is relatively safe and is regularly used in the aquaculture industry to treat food fish for diseases. Salt has been successfully used to treat minor fungal and bacterial infections, as well as a number of external protozoan infections. Salt alone will not treat whitespot (Ichthyophthirius) or Velvet (Oodinium) but will treat most other types of protozoan infections in freshwater fishes.

You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate (4 heaped tablespoons per 20 litres) will affect some plants and some snails. The lower dose rate (1-2 heaped tablespoons per 20 litres) will not affect fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.
 
update: That one fish didn't make it overnight.

Normally when fish start spinning through the water, they have an internal infection in the brain. It is usually protozoan based, although it can also be bacterial or viral, but normally it's protozoan. This is caused by over crowded tanks, dirty tanks, dirty filters, or lack of water changes, and there is no cure.

The tank I keep pretty clean, the water is always clear and like I said regular water changes. I only feed the fish every 3 days or so, and only so much as they eat it all within like half an hour or so. There were 3 cory's in the 10G tank. [Because they are getting larger I was starting to feel bad because the school was getting small, but also didn't want to add any more fish because of the small tank size. I had actually been in search of someone who had an established healthy tank that we could give them to, Or had been considering getting a bigger tank so we could get more fish to add, but don't really have room for a larger one.]

The filter however, was pretty gross. I try to only replace the actual filter cartridge when absolutely needed, and try to just swish it in the old tank water when doing water changes, but I know cleaning with tap water kills all the bacteria anyway, so what is the best way to do this?

Going forward - how often do you change it versus wash it? How gross is too gross and how do I know? Previously I tried to keep it as long as water was able to flow through it, without flowing over the top of it inside the filter.

EDIT: I did just put in a new filter cartridge last night
 
update: That one fish didn't make it overnight.



The tank I keep pretty clean, the water is always clear and like I said regular water changes. I only feed the fish every 3 days or so, and only so much as they eat it all within like half an hour or so. There were 3 cory's in the 10G tank. [Because they are getting larger I was starting to feel bad because the school was getting small, but also didn't want to add any more fish because of the small tank size. I had actually been in search of someone who had an established healthy tank that we could give them to, Or had been considering getting a bigger tank so we could get more fish to add, but don't really have room for a larger one.]

The filter however, was pretty gross. I try to only replace the actual filter cartridge when absolutely needed, and try to just swish it in the old tank water when doing water changes, but I know cleaning with tap water kills all the bacteria anyway, so what is the best way to do this?

Going forward - how often do you change it versus wash it? How gross is too gross and how do I know? Previously I tried to keep it as long as water was able to flow through it, without flowing over the top of it inside the filter.

EDIT: I did just put in a new filter cartridge last night

The death of the fish is not unexpected, it was pretty far gone from the description.

On the filter question, rinse the media (cartridge, foam, whatever) at every weekly water change. Replace it when it is no longer providing filtration, i.e., when water can get around it rather than being forced through it.

I rinse filter media under the tap. Once the tank is established (yours at two or more years is established) this is not going to kill off the nitrifying bacteria, as they exist elsewhere in the tank (in the substrate for example). However, if it makes you feel better, rinse it in a bucket of tank water. If you have live plants, they are removing ammonia/ammonium too, and depending upon the number and growth rate, they might be out-competing the bacteria and it is even less of a question.
 
You can buy sponges for other brands of filter and use a pair of scissors to cut the sponge to fit in your filter. Sponges last for years and don't need replacing unless they start to fall apart.

Filters should be cleaned at least once a month unless they are new and less than 6 weeks old. New filters should not be cleaned for the first 6 weeks because you can disturb the bacteria that are trying to grow.

When you do clean a power filter, take the filter media/ materials and squeeze them out in a bucket of tank water. If the media is really dirty you can squeeze it out in a second bucket of tank water. When they are clean you can put them in the tank or a bucket of tank water while you wash the filter case and motor under tap water. Then set it back up and get it going.

Try not to replace filter media because you get rid of the beneficial filter bacteria when you get rid of the old media. This can cause ammonia and nitrite problems that can kill the fish.
 
oh boy.....

now the other two fish are swimming up and down like the first one did a few days ago. (I'm trying to figure out how to get a video on here), but they don't go all the way to the top, just like up the wall a ways and back down.

AND I was looking at one of them and his little whiskers are like all gone :( I checked everyone thoroughly 24 hours ago and this wasn't there. What on earth could have happened to him?

did another 50% water change today and added salt to the new water to keep the concentration the same.

here is a pic of the one poor guy without whiskers and a general pic of the tank with ALL the lights on (the directions said to turn everything on to show in the pic, but this feels like an operating room lol. I never use the hood light unless I'm looking for something, and it sits against the wall out of direct sunlight and there is only the filtered natural light from the room). The plant on the left thats uprooted is a lower plant that's normally near the bottom of the black rock to give more hiding places
PXL_20210724_165343306.jpg

PXL_20210724_165744806.jpg


and edit: ps my son picked the rainbow lily pads that clearly match the rest of it :)
 
You can upload videos to YouTube, then copy & paste the link here.

Do a 75% water change and gravel clean the sand every day for 2 weeks.

Add 2 heaped tablespoons of salt for every 20 litres. Keep the salt in there for 2-4 weeks.

The big daily water changes will help to dilute any disease organisms. The salt should help kill any remaining disease organisms.
 
OK so mostly, they still are swimming around normally on the bottom. I sat by the tank for like 30min waiting to get a "good"/bad clip. This one the one guy like actually nose dives real hard. I haven't seen that before or after this video thankfully.

(so I'm apparently old, and this is the first thing I posted to youtube, feedback plz if it doesn't work)
 
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OK so mostly, they still are swimming around normally on the bottom. I sat by the tank for like 30min waiting to get a "good"/bad clip. This one the one guy like actually nose dives real hard. I haven't seen that before or after this video thankfully.

(so I'm apparently old, and this is the first thing I posted to youtube, feedback plz if it doesn't work)
Great video anyways whether its the first time or not ...
If the swimming patents persists try to put it in separate tank and observe if the same behavior happens.
 
There is nothing wrong with catfish swimming around the glass like that. It's just the fish checking out the tank. I see it all the time with catfish in tanks.
 
I know that they do the exploring sometimes, but the reason for the original concern is that they were doing it much more frequently than normal. Like, for these fish in this tank, it is a behavioral change - which then led to that other fish getting far worse and worse, then dying. So that and the loss of their whiskers is my reason for concern at this point.

I will keep up with the big daily water changes and keep the salt in for 2 weeks then taper out.

**But any thoughts on his whiskers? (Or I think they might be called barbels?) last week they were nice and long and hung down on the sides, and now they are like... gone, and nothing goes down past his mouth opening. Could that have been the same fungus/bacteria/protoza whatever that caused the other fish to die?

I'm guess no, but do they grow back?
 

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