Colu

A little more information would be helpful what are your water parameters ammonia nitrite nitrate etc and can you post a picture of the fish to marks on his head @ccmay

@Guppysnailkeeps heterandria Formosa can answer about how quickly they breed and tank size

Endler guppies mosquito fish would all be good choice

The best advice I was given was Take your time don't rush do your research the best advice I would give is test your water parameters weekly and do regular water changes and live plants are the best filter you can have for your tank and take your time researching the fish you want go with fish that best suit your local water parameters don't try and change your water parameters you will only stress your fish out in the long run and relax and enjoy your fish

He some information on breeding them I found

If you want to dose the tank with with paracleanse before adding new fish to kill any suspected parasites you can do that nitrite poisoning can cause hanging near the surface rapid breathing lethargy loss of Gill colour orange coloured poop can be caused by the food your feeding you usually get white stringy poop when your fish have parasites ammonia can cause scale damage bottled bacterial doesn't do anything speed up the cycling process when you add new fish if you get ammonia or nitrite spike you want to do is test daily and daily 50% water changes and add a double dose of prime every 24hr to help detoxify any ammonia or nitrite till they constantly stay at zero

Paraguard isn't a very effective medication for treating flukes you would want to treat with prazipro or paracleanse as you did a fish in cycle that could be the cause of some of your losses some of the symptoms you describe can be caused by ammonia and nitrite what were you water parameters when you started to lose fish what I would do is get a bottle of Dr Tim's ammonia or add a small amount of fish food daily to cycle your tank before adding fish you want to see a raise in ammonia and nitrite then a raise in nitrates to about 10-20ppm and then zero ammonia and nitrite before adding more fish and gradually add fish don't put them all in at once add two lightly feed and test your water for a week then add two more @Alexis22

Looks like an injury you could add some aquarium salt 1 table spoon for 5 gallons and monitor it should get better on its own with good water parameters low stress environment @Lennie

Tetracycline would would work it would be more effective in food he's a food recipe you can use with tetracycline@Goshfush

I feed mine a combination of cucumber spinach lettuce algae wafers EBO youngest grow paste and spirulina paste EBO veggie sticks brine shrimp and theirs plenty of wood covered in biofilm for them to gaze on @AllFishNoBrakes

Over the years when I had sick fish the recommended treatments weren't very effective so I started to read a lot of books and articles on the subject and read up about the active ingredient in the medication to find the most effective treatment so self taught when you have kept fish for over twenty years you pick up a few things disease is one of the things every one who keeps fish will encounter at one time I find prevention is better than cure always quarantine new fish good water parameters good quality food live plants correct tank size will all help to reduce stress in your fish and prevent disease out breaks

It's difficult to say whether it will spread with out knowing exactly what the cause is you can get the medication I recommend off Amazon I would definitely recommend quarantining them even if you decide not to treat

What I would do is daily 25% water changes and add a double dose of prime till your ammonia constantly stays at zero the symptoms your seeing could have been caused by an ammonia spike when you were away what I would is 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 relaxants and will also reduce any possible fluid buildup causing the bloating @Denied Taco

What are your water parameters ammonia nitrite nitrate etc and how long has the fish been bloated have you tried fasting it if so did you notice any improvement @Denied Taco

It could be your high levels of nitrates it looks like 80ppm to me high levels of nitrates can effect your fishs immune causing secondary infection rapid breathing lethargy poor feeding response loss of colour what I would do is cut back on the easy green as that adds nitrates to your tank increase water changes add a double dose of prime that will help to detoxify any nitrates till get your nitrates below 40ppm I would aim to keep your nitrates between 20-30ppm @Staceyh527

Fenbendazole

Could be an internal growth or a bacterial infection causing inflammation of the surrounding tissue what I would do is quarantine and do a course of kanaplex in food feeding a small amount twice a day for 7 days

As his lips are swollen Frist thing I would do is a course of maracyn2 active ingredient minocycline has anti-inflammatory properties that will help reduce some of the swelling and salt 1 table spoon for 2 gallons @GoYankees10

Welcome to the forum nice Javan fern jungal

What I would do if you can is quarantine the neon tetras and treat with aquarium salt 1 table spoon for 2 gallons and do a course of maracyn2 in food if there struggling to dose tank

What are your water parameters ammonia nitrite nitrate etc have you added anything new to the tank recently any rapid breathing listlessness hanging near the surface flashing loss of appetite @Staceyh527

As long as it has some flow going though the sponge it should be fine

I was reading about these recently apparently they are easy to breed using spawning mops or Javan Moss maybe you will have some baby stone cats further day the road

What I have would do is have an empty tank to hand and have a spare sponge filter running in the main tank if disease pops up you can add water from your main tank to the quarantine and the spare sponge filter that will be colonize with benefial bacterial it doesn't need to a big tank 5-10 gallons depending on the size is of fish you will be treating

Some medication such as kanaplex aren't heat resistant I would be careful with using heat with any antibiotic medications @cinnanoodles