I was reading the thread on salt, because it was about my problems, too.
I have a 20 gal. tank with a Whisper Filter system and a UV filter and a bubble system designed for betas. I have between 15 to 20 females and one male. I also have tetras...two types, I forgot the names, but they are tough and fast. However, I like the neon tetras the best, and they will do well if I have 12plus.
I have this algae eater that was small 1 inch when I bought him. Now he is 8 inches long.
I know the betas...I'm not crazy, they have a personality. There only problem is nipping at each others fins. Now and then I add that "Natural" medication that kills all bacteria infections. Things always clear up, but after the 1/3 water change, I always lose 2 or 3 betas...the weaker ones.
So I went to the salt/raise the temperature method. This works for my betas, but I had 8 catfish, and 6 died over night. Also, something kills my neons, slowly... maybe 1 every 10 days. I can replace both of them because I like the neons, and need the cats. I get white ones, spotted ones, striped ones, etc.
Who is dying because of the salt.? Nothing heals up the betas better. No "ich" as I keep the temperature at 84.
Firstly your tank sounds overstocked and badly stocked. Male and female bettas should not be kept together. Females can live together in what is called a 'sorority' but it is a recipe for disaster having a male in there.
The nipping of fins may be normal (bettas are aggressive fish and some fighting is to be expected) or it could be because of overcrowding and stress.
Stop with the medications. You should not be getting bacterial infections in a well-established tank, or at least not as often as it sounds like you are getting them.
What species is the algae eater? If it's a common pleco it is going to quickly outgrow a 20 gallon tank and will need to be rehomed.
Have you ever actually tested your water parameters? I am thinking the root cause of all your problems is poor water quality and improper stocking.
Stress can lower fish's immune systems and make them more vulnerable to disease and illness. I see a number of possible stressors in your tank, the greatest of which being that you have way too many fish in a 20 gallon tank.
Salt can also weaken fish significantly. Prolonged use of salt can do a lot of damage to fish's internal organs, as well as cause bacteria to become resistant to salt. The same with all types of medications.
If you don't know the identity of your algae eater, we can help ID it if you post a picture. But based on description of size and growth size, it is most likely a pleco, which is ill-suited to the size of your tank.
I have other 3 gal. Fluval tanks in which I keep one male Betta and a small catfish in each. I clean them, and feed them...that's it, nothing else, and they all do fine.
I want to take the prettiest female and mate her with a beautiful male who keeps making bubble nests.
Back to the 20 gal. tank, the bottom half is constructed with thick fake plants, coral, and many figures designed for hiding and escaping.
I should forget the Neons ? There are two sets of females; one alpha bunch who do not mess with the alphas; the others have their own space, but will give it up if challenged. Two pet shops always have beautiful female bettas, so I will replace the couple/three that did not make it.
I know how to mate the bettas. Should I go ahead with that plan?
I just do not want to take the Pleco out and shoot it...so what do I do with him?
Address the mating idea with the beautiful Blue Male in the 3 gal. Fluval. He is always blowing bubble nests. I have some pretty females, and from one of that group I want to mate them in the small Fluval?
If you have fish dying you should not be making more. I think you are better off investing in a 40 or 55 gallon tank to keep your current animals happy. Replacing fish constantly means you have a problem.
Two "pretty" fish can produce bad offspring. There is a lot more to genetics than pretty and ugly, red or blue.
Have you ever tested your water?
What kind of catfish do you own in your 3 gallon? That's a very broad term, spanning from tiny specks of a fish to monsters that weigh hundreds of pounds. No matter, a 3 gallon can only hold a single betta as is. Posted via Mobile Device
Hey Eboydell, what part of New Orleans are you from, if you don't mind me asking? I live on the westbank in Marrero. And it sounds like your tank is very overstocked for 20 gal. I'd try to re-home or invest in a bigger tank.