Colu

Have you seen any rapid breathing listlessness hanging near the surface and how often are they flashing @LDZ

I think at this point it would be worthwhile doing course of kanaplex or maracyn2 and I would also add some Indian almond leaves as they have antibacterial and antifungal properties depending on the quality of the leaves you will have to add one leaf per gallon to get a beneficial effect

Looks like a minor injury to me it should heal given time you could add some Indian almond leaves as they have antibacterial and antifungal properties @Gannon

It looks like columnaris but the fact it's been going on for a couple of month means we can rule out columnaris that would have killed all your fish by now what are your water parameters ammonia nitrite nitrate etc do use a water treatment like prime when doing water @BGoodyFish

What I would do 3% Hydrogen peroxide leaving them to soak for 24hr before rinsing them with dechlorinated water @Clo

Looks like velvet the most effective treatment is copper based ick X isn't very effective treatment for velvet i would treat with Fritz copper safe you will need a copper test kit to keep the level of copper safe at a therapeutic level of 1.5-2.0ppm @BGoodyFish

What I use is a 3% hydrogen peroxide solution hydrogen peroxide breaks down into H20 and oxygen within 48hr just give the tank a rinse with dechlorinated water @Tam

What species'of goby is it love the violet coloured fins

What are your water parameters ammonia nitrite nitrate etc as cloudy eye is commonly caused by water quality it can also be caused by an injury to the eye @billango

I think it's safe to start adding some fish I would feed them very lightly in the first week and keep a close eye on your ammonia and nitrites if you register any ammonia or nitrites than I would do a 50% water change and add a double dose of prime to help detoxify any ammonia or nitrites every 24hr till your ammonia and nitrite constantly stay at zero after a week if you haven't had any ammonia or nitrite spikes I would add a couple more fish

With the redding it more than likely bacterial infection I would treat with kanaplex or maracyn2 if no other fish seem affected I would quarantine and treat if you can

I would do Epsom salt baths 1 table spoon for 1 gallon for no more than 15 minutes for 5 days as Epsom salt acts as a muscle relaxant to relieve pressure on the swim bladder @dasaltemelosguydid some interesting experiments with sound frequencies to help fish with swim bladder maybe he could chip in with some useful information

Have you seen a rise ammonia then it gradually go done to zero

All you can do at the moment is wait for the medication to work he doesn't look good I don't think he's going to recover if you think he's suffering i would euthanize him with clove oil

Yes do two table spoons of salt add the almond leaves

I would start treating with aquarium salt as @Chick-In-Of-TheSeasuggested if your going to use a quarantine tank I would up the level of salt to one table spoon for 3 gallons and add some Indian almond leaves as they have antibacterial and antifungal properties after 1 week give an updated @knee

Most comprehensive book I have found on dwarf cichlids is cichlids atlas volume 2

Looks like part of an Elodea to me

I would do a daily water changes and add a double dose of prime every 24hr till your nitrites constantly stays at zero any nitrite is harmful to your fish it doesn't look like a fungal infection bettas are heavily inbreed they are prone to developing tumors or benign growths that what I think this is as it been slowly getting bigger over 6 months if you don't have live plants I would add some aquarium salt 1 table spoon for 3 gallons for two week just remember to only put back in the amount of salt you take out so if you do a 3 gallon water change put one table spoon of salt back in I would also add some Indian almond leaves as they have antibacterial and antifungal properties depending on the quality of the leaves you might have to add one leaf per gallon to get a beneficial effect and update in one weeks time @MorganJayne

If your fish haven't had any rapid breathing listlessness hanging near the surface flashing spitting food out sunken belly or had fish randomly die every couple of weeks I wouldn't worry about your fish having parasitic infection @Schuyler

Usually when you get the stage of pineconing that's usually caused by kidney infection polycystic kidney disease kanaplex is a good antibiotic for treating kidney infection as your fish haven't responded to kanaplex I would do Epsom salt baths 1 table spoon for 1 gallon for no reason than 15 minutes for 5 days and do a course metroplex that treats anaerobic bacterial that can cause some of the symptoms associated with Dropys I would check your main tank if your getting multiple fish developing the same symptoms is their anything causing stress that can weaken their immune system leading to secondary infection what are you feeding and how often have you had any ammonia nitrite nitrate spikes do you have a heater on your tank as large swings in temperature can stress fish out leading to out breaks of disease @RadMax8

I would test your water parameters just in case something off as high levels of nitrates can cause bent spines in fish make sure theirs no ammonia or nitrite if they are fine It could be a secondary bacterial infections I would do a course of kanaplex or maracyn2 they are more broad spectrum antibiotic treatments and add a Small amount of aquarium salt 1 table spoon for 5 gallons at that level it shouldn't harm your plants and will aid Gill function and add essential electrolytes I would also add an extra air stone during treatment to increase levels of desloved oxygen have proven to reduce mortality rates during treatment

High levels of nitrates can effect fish's swim bladder if it was getting to 80ppm for a long period of time this could have damage your fish's swim bladder some internal types of internal parasites can also effect fish's swim bladders and cause sunken belly that can be a sign of wasting disease I think it would be worthwhile treating for parasites @Odd Duckhas a good treatment schedule I think it would be worthwhile to follow this treatment plan

They are stunning

It could be wasting disease with what your describing what I would do is treat all your fish with expel p once a week for three weeks and add a small amount of aquarium salt 1 table spoon for 5 gallons that will aid Gill function and add essential electrolytes it has also proven increase levels of desloved oxygen can increase the efficacy of medications and increase survival rates I would add extra air stone to your quarantine and main tank @Fishy101