Bala shark in trouble! Help!!

So I've had my Bala for over a year now... He has gotten big, & he's beautiful& my favorite! A month we bought a baby Bala so he could have a friend, & 2 days ago it died unexpectedly...the very next day-my remaining Bala started trying to jump outta the tank...he has a boo-boo on his nose from hitting the hood above the tank. So I went out to a specialty aquarium store, had my water tested... The nitrates were very high! I bought something to bring down nitrates, I bought 4 new live plants- to help keep nitrates down... I bought 10 gallons of special water that several people recommended to me as well as aquarium salt because the water was a little hard. Did water changes 3x in 48 hours! Added everything I was told, changed my filters-even though it was way b4 time. McShark seemed to perk up almost immediately! Then, I got up this morning & checked on him- he has white spots that almost appear as bubbles on one side only! He's not eating- a huge giveaway with him that something is wrong! So 3 stores, 2 trips to one of them- $100+ later- he still seems sick! Please anyone who can help! I love my McShark & really wanna save him! If I can figure out how to attach pics will do

looks like ick

I need to make a few comments.

Bala sharks are shoaling fish which need to be kept in a group in a HUGE tank. Being on its own is stressing the fish and stressed fish become sick more easily than non-stressed fish. It may also be stressed from being in a tank that's too small.

Nitrates are kept low by water changes, not overstocking the tank and not over feeding the tank. Can you tell us please how big is the tank, what it in the tank besides the bala shark and how often & how large are your water changes?
What did they sell you to reduce nitrate?
Plants take up ammonia so it isn't turned into nitrite then nitrate. They are unlikely to remove nitrate that's already there, though if there are enough plants they can stop it increasing.

Special water is meaningless unless you know what's in it. Can you find out what exactly is in this 'special' water? Was it RO water, as that dilutes hardness and changing the hardness suddenly will stress fish.
And salt will do nothing for hardness. All salt is useful for is a mild antiseptic.

When you changed the filters did you change everything? Throwing away filter media is throwing away bacteria.
What are the ammonia and nitrite readings in the tank water?

I agree completely with @Essjay . And, this is ich, so raise the tank water temperature to 86F (30C). You can turn the heater up to achieve this, but also do a significant water change and use warmer replacement water to help raise the temperature. Increasing it during today until it is 86F this evening is OK. Maintain the high temp for two full weeks. Water changes can be done during that time, just keep the replacement water at or slightly above 86F. Clean into the open substrate areas during each W/C as this will remove some of the cysts before they "hatch."

We don't yet know the other fish in this tank, but increasing the heat for two weeks is safe for most tropical fishes, and it is the safest and most effective treatment.

Understanding the life cycle to ich is the only way to ensure you know how to treat it. Ich has a lifecycle. You can only "attack" or treat ich in certain stages of it's life. Figure out that cycle. And look up treatments. Most stores have an "ich treatment" but that treatment is useless if used incorrectly at the wrong time. Ive cured a tank with over 10 platys once that had ich for almost 3 weeks. I only had one fish die and it was arguably my fault.

Good luck !

We still do not know the size of the OP's tank, though it seems unlikely it's 125 gallons or more. I hope once the shark is cured, no more are added as "friends", particularly significantly smaller, younger Bala sharks. The larger one will almost certainly kill it/them.

As others have said, this does present as ick with a secondary infection where the tomites have left open sores, making it look a little blotchy. However, ick seldom appears asymmetrically as you described if it has reached the level of infection we see in your photo.

Spitballing in an effort to help. You said it looks like bubbles. You appear to have a bubble wand or a very large airstone, are there lots of microbubbles in the water? Stressed fish will often produce more body mucus as a response, multiple water changes in short order with water conditioners that have a stress coat might compound this condition. On rare occasions, I have observed bubbles temporarily adhering asymmetrically to stressed fish hanging out in bubble streams. Is the Bala shark generally orienting itself with the "bubbly" side toward the airstream or hanging out in it?

As ick also attacks gills and I am not suggesting reducing air, just suggesting that might be why you are observing asymmetric "bubbles" on your fish. Both could happen simultaneously.

The article mawisafish cited is very good. Like other organisms, ick parasites have evolved to survive, so the longer there is an active infection the more likelihood there will be a multitude of cycles with numerous waves of the parasites. This is generally why medication packaging recommends prolonged treatment, there is no way of knowing exactly where you are in the parasite's lifecycle when you begin treatment or how many different cycles are in play. Prolonged treatment is more likely to catch the multiple waves of the parasite.

Going with what Essjay said, Gala sharks can get up to a foot long and need a tank of 120 gallons or more with a nice shoal (I don't know a good amount)... My neighbor kept one once but it died cause it was alone and in a 10 gallon... To be fair he is a nice guy and he didnt know what he was doing... If you cant get a 120 gallon tank amd more balas, I suggest you treat the fish and then return him to your LPS

@shandanielle77 what is the word, has your bala improved?

One trick that helps cure ick? When you make water changes,siphon water from the bottom substrate. That's where the ick eggs are.
The last time I saw ick/body fungus I tried an inexpensive remedy..ridX I think it was. It was a blue dye med but it worked. Raise the water temperature also.