I just did a 30% water change on Diablos tank. With him swimming around, the attached "whatever it was" is now gone. Hopefully it was just poop now that I know where his vent is..you are probably right. He does look a bit bloated in that area,( I compare him to our other Betta).So, is it from too much food at one time..I didn't think he was eatting that much. The guy at the pet store suggested feeding every three days, I do not agree. I believe a little each day, I wouldn't like eatting every three days so I will not do that to them either.
I will follow the water change info provided, but..... We are on well water via
a community system in the mountains. Since you suggested the water
change more often I thought about the water before it even gets into the
tank. I get it from our filtered system through the refrigerator, heat it to 80 and put it in the tank. I TESTED IT BEFORE PUTTING IN THE TANK..it
has the same PH and ALKALINITY as what was in the tank. So now what?
Use bottled water..or how do I change the PH and AK in the water before
I put it in the tank
Thanks..

oh yah....no de clorinator used(what is it used for/)