Bubbles stuck to betta?

What are your water parameters (tank & tap)? How long has the tank been running? Can you take pictures of your betta?

When you say covered in bubbles, could it just be oxygen that was stirred up by your water change? When I pour water into my tanks during changes, little bubbles pop up on lots of plant surfaces. Did you betta play in the water going back into the tank?

I do not have experience with the medications you are referring to, so I can't help there sorry.

Again, pictures would really help...

I'm glad the bubbles have gone away. Definitely keep an eye on his scales. Do you give your fish fasting days? I find bettas really benefit from a day or two each week with no food and feeding minced bits of cooked deshelled peas two or three times a month to prevent constipation/bloat. I've never heard of bettagran, but swear by Hikari Bio-Gold pellets...

How are you feeding your cories? Every betta I've known will take advantage of ANY type of food source that hits the water, algae wafers, flake, etc. and has a tendency to overeat because of that.

You should age your water for a day or two before doing a PWC from now on.

It sounds like your tap water has a very high level of dissolved gases and you should allow the water to outgas before using it in your tank... especially when doing larger % water changes. Doing 25% of less is usually safe regardless of the difference in water parameters but when doing more than 25%, you should know your 48 hour tap water baseline and if the numbers right out the tap are a lot different than after 48 hours, you should limit the size % of PWC's.

For example, a tap water with a high level of dissolved CO2 in the water will test with a much lower pH right out the tap... due to the higher level of CO2.. but then after 24-48 hours, the CO2 level will stabilize and the pH will usually go up quite a bit, unless the buffers added by the water utility also change once out of the pipes. Other tap water will have a very high pH usually due to the buffers added by water utilities and the water could have a very low CO2 level in the pipes but once the water is exposed to air, CO2 could ingas into the water and lower the pH.

These dissolved gases, if added to a tank at too high of a level can cause an embolism in fish when they breathe in the water... kind of like how scuba divers get the bends when air bubbles expand in their blood vessels and joints when surfacing too quickly. This could be why your Betta was feeling bad and eventually the air bubbles worked their way out since fish do have osmoregulatory systems that us humans do not have.

My fish all get this when I do wc's, due to the dissolved gasses in the water. It's never caused a problem and it quickly goes away once the water is off-gassed. I do large wc's and don't age my water due to using a python.

Do a Google search for - fish embolism dissolved gases - and read the scientific reports about this problem. It's a real problem that doesn't cause a problem *most* of the time when the level is not too high and it only affects the fish short term but in more severe cases, it can be toxic.

I use a Python myself since I have multiple tanks... and use to have even more... during the summer months or the coldest times of winter, I refill my tanks very slowly and I can see bubbles forming on the inside of the Python hose so by the time the water comes trickling/splashing out into my tank, I know it's been outgassing a lot already. Then, by re-filling the tank slowly, splasing into the tank, with the filters running, the water gets further agitated and I've never seen the bubbles forming on the inside of my tank glass... or on my fish.

Without testing the water right out of your tap, it's hard to tell if you have high CO2 or high O2 or some other gas... which could be even more dangerous. You might be able to find out some information from your water utility. If you have well water, your county agent might have better testing equipment.

For a single tank of 10G or less, a 5G bucket or a 5G water bottle will work fine. Don't fill the water bottle all the way... maybe just 3G-4G... since you want a lot of surface area to allow for outgassing/ingassing until the water is stabilized. 24-48 hours is enough but if you have an air stone that you can run in the water, that will agitate the surface and allow for faster outgassing/ingassing.