Ok, THANKYOU. I hugely appreciate specific advice.
From racoll...."bombarding him with different types of food in the hope that he likes one of them is highly likely to pollute his tank. You understand about aquarium cycling and new tank syndrome, right?"
No, I do not have any aquarium experience-zero. This information did not come up while learning the care of the turtle-her water is not tested or adjusted the way aquarium water is, I just keep her water crystal clear through the Fluval FX-5 and there have never been issues. I properly care for her by cleaning the fluval out every few weeks when I'm supposed to. It does have a layer of biological media in it that hosts bacteria good for her water- I now understand this is part of the cycling you are talking about. I will google aquarium cycling and new tank syndrome to read today so I gain full understanding of this topic.
About using her biological media to jump start Nacho's filter, a cool idea but wouldn't you be worried about introducing pathogens from the turtle's tank into weak sick likely immunocompromised Nacho's environment? Couldn't I even be risking introducing salmonella into his tank by doing that? (she's a red eared slider, I was warned they can be carriers of it).
Some sources said to offer south america catfish food twice a day, or at the least once a day...I'm assuming that's how often it is normal to feed fish. Given what you have emphasized about New Tank Syndrome and his reluctance to eat because of shock right now, I will pause offering food for a few days as you advise to give him a chance to adapt and adjust.
from racoll...."Give him a few days to get used to his new environment, then try a small worm. You can feed a worm every couple of days after that, and gradually more once the filter has matured. Try to be patient! After you start feeding him, make sure you change 10% of the water daily so it doesn't get polluted."
OK, thank you SO MUCH for all of this specific advice, I will definitely follow all of these suggestions. This sounds like a reasonable game plan. The only part of it I have reservation about it using the turtle's media to jump start Nacho's new filter. I will read more about tank cycling. The benefits may outweigh the risks, I guess its something I need to more fully understand. I worry about the infectious disease risk.
from Birger...(quoting me)"I am hoping someone with actual expertise who will give specific advice weighs in here soon"
hehe...you do not get much better then Racoll !!
I did not mean that in a bad way. I understand that this is a community of high level hobbyists, professional tank artists, scientists and researchers. Most people here have high level of specific knowledge in their field. But my statement was in reference to someone with knowledge giving SPECIFIC ADVICE. I was thinking no one was writing me any specific answers to numerous questions because they didn't know what kind of fish this was or what to do with him. Perhaps that was an incorrect assumption.
I have very very little knowledge about this intimidating chemistry oriented area of animal care. I have mostly cared for mammals my whole life. The reptile that I have has had very little water issues because I paid a fortune to buy quality materials to set up her home and I do the work to clean everything when it is supposed to get cleaned and buy fresh fluval filter pads, etc. Her water looks like bottled water all the time. I know almost nothing about this world of tank cycles and adjusting water pH. I took a day off from my work yesterday just to begin self education about what this fish could be and some of the chemistry involved. It is a very involved topic, and I'm actually a pretty fast learner. I am very grateful that both you and racoll have written comments today with more specific advice-thank you so much for taking the time to do this. It is very valuable in this awful situation.
from Birger...."An air bubbler will help a lot and continue to do the water changes until you get a functioning filter going...even then the water changes are good to do but to be specific no more than 40 % at a time if changing daily..."
Thankyou. I was actually on the fence about if I even needed that bubbler, it wasn't clear. I will keep it on board and get it going after I get the needed valve today. And that is good news about the amount of water to change out, I was doing around 30-40% water change daily. I will go return this piece of junk filter and purchase one of the fluval aquarium filters they have for the $100-$140 range to start getting this going in the correct direction.
Once the fluval is up and running....
from racoll.."After you start feeding him, make sure you change 10% of the water daily so it doesn't get polluted."
Yes, understood, this is for safety until the good bacteria set up home in his filter and I get a natural cycle going. I will do this.
from racoll..."I say "he", but I don't know that for a fact; Nacho seems like a guy's name."
His abuser referred to him as a "he". If this fish is indeed a iridescent shark catfish, everything I read about them yesterday says sexing them is impossible, so his actual gender would be an unknown. I think his abuser named him Nacho but its actually a very cute name and he has a following now, many people know of him and are routing for him to survive so we will keep the name
Birger, the abuser is not my neighbor. I am safe many hundreds of miles from her. When we spoke once it was on the phone and shortly afterwards I was talking to AT&T's legal department on how to take action if harassment began. My only interest in talking to her a second time was to attempt a better identification-to get more information on his origins and what he really is. I am OVERWHELMED by the biodiversity of this general term "south american catfish". I guess people here are used to it, but for someone just learning, it is staggering to comprehend the amount of subspecies there are and how different they are. The reality is I do not even understand if he is a carnivore. That is something I was really struggling with yesterday- could his condition have been so poor because she was feeding him omnivore fish flakes when he was meant to be a vegetarian? It sounds like you all worry about this much less than I do. It also sounds like it may be reasonable at this point to assume he is a badly abused growth stunted iridescent shark catfish and just work from there.
from Birger.....stability stability stability!!
from racoll......the biggest risk now is killing him* through kindness. Clearly he needs food, but overfeeding will kill him within hours. It's not so much what he eats, it's what he doesn't eat.
Based on what you are both indicating here, the plan is:
1.) stop all feeding for at least next 48hrs.
2.) all excess floating food has been removed from the water via a fine fish net-its gone.
3.) while no fluval filter is active, daily water changes can continue not to exceed 40% of water a day.
4.) when a fluval filter is active and he begins taking in food again, daily water changes can happen at about 10% of water a day until a good aquarium cycle is established (which I will now read about extensively today).
Here is my ONE remaining question from today: in my shoes, would you add some of the fluval biological media from my red eared slider's active filter into the Nacho's new filter? Would you take that infectious disease risk to get the benefits of an established aquarium cycle and the needed good bactieria? Or would you give more weight to the seriousness of Nacho's poor health (immunocompromised state) and the fact that he is a walking target for any pathogen right now?
Thank you SO MUCH for your time and help. I am immensely grateful, as is Nacho I'm sure. He clearly wants to live. He is showing us that.