Possible swim bladder disease and treatment

Question
Please could you help with a question about some sick fish?

We have a 175 litre tank with balloon mollies, platies, neon tetras, black phantom tetras and a dwarf gourami.
Our youngest ballloon Molly (born in the tank) has been swimming along the bottom of the tank and listing to the side.   Today he has started 'corkscrewing' through the tank but still seems to have some sense of direction.

One of the platies is also sitting on the bottom of the tank and gasping, still swimming occasionally but lethargic and only seems to be able to swim across the floor.

Do you think this sounds like swim bladder disease? The baby Molly has still been eating and his poo looks normal so it doesn't look like a digestive problem hopefully so We are proposing to use the Interpet swim bladder treatment. It recommends adding 5g per litre which seems a large amount for a tank this size, do you have any tips on how to introduce this level of salt without endangering the fish? We are due to do a 30% water change today, do you think adding this much salt into the replacement water (over 2 days) would be safe?

We have recently used the Interpet anti-white spot medicine (some of our fish have been flicking, no visible ich but but our fish store thought it sounded the most likely cause) but the treatment finished 9 days ago so we think introducing  for swim bladder at this stage should be safe. Some of the fish are still flicking but no related deaths or other ill-health effects so far.

Our water test yesterday showed the following results:
Nitrite 0
Ammonia between 0 and 0.25 (hopefully will be brought down by today's water change)
Ph 8
Nitrate between 10 and 20

If you have any answers to these questions or any other suggestions about how we can help our fish we'd really appreciate it.  Many thanks.

Answer
Hi Yvette,
Its difficult to say if your fish do indeed have swim bladder disorder. Often, it is more simply a symptom rather than a disease in itself. Various things can interfere with the swim bladder, constipation can put pressure on the swim bladder. It is actually the most common reason fish develop swim bladder problems. Internal infections, tumors, and even high nitrates can often be to blame.

I really hesitate to recommend medication because it can do more harm than good. We aren't sure what we are treating for.

The strange swimming behavior may be related to a different internal problem. Like a nervous system problem or something quite complicated.

Also keep in mind its very possible they are stressed out by the previous medication usage. Fish will 'itch' themselves if the water quality is bad or there is a chemical irritant in the water. It doesn't always mean parasite problems. Until spots actually show up on the fish I would recommend refraining from treating for white spot.

If there is trace amounts of ammonia that can be irritating their skin and stressing them out. Testing the water regularly and doing water changes to prevent ammonia from building up too high is your best bet.

Medication usage often kills off the good bacteria in your system. So thats where poor water quality can erupt from.

Try doing some daily 30% water changes for a week or so. See how they do. Sometimes extra clean water will help fish pull through.

Keep a close eye on them. They could be coming down with an illness.

Good luck!
Susan~