hello, I have a calico pearlscale and he has this small fluid sac attached to his side. It's on the middle left side of his back. The sac is clear and about the size of an eraser head of a pencil. I have never seen anything like this before. I've been on a few websites, and haven't seen any pictures or anything like it. He's fully active and acting the same. All the water perameters are good, (nitrates, nitrites,ph, temp, ammon, etc) The only thing different about my water is that it is a bit cloudy the past few weeks, with a light white haze? In my 30 gallon tank I have the pearlscale, a telescope eye and a fantail. I syphon 10-12 gallons of water a week for tank changes. The other 2 fish are fine as well, just the sac on the pearlscale. . .any advice is appreciated, thank you!

Columbo, if the sac is clear, not red, you can easily pop it. Here is how it goes....
Prepare a bucket, filled with tank water, have a thin needle ready, as well as a small amount of store bought hydrogen peroxide, as well as a cotton swab and an antibacterial cream.
Get the fish out of the tank, hold him gently, but firm over the bucket (in case he slips your fingers, he will not land on the floor . If you are right handed, hold him with your right hand, and vice versa.
Now get the needle and pop the sac open. The fluid inside will run out. The bucket comes in handy again, since whatever fluid is in the sac will not run back into the tank that way, it will go into the bucket, and not infest your tank further.
Now, dab the cotton swab with peroxide and swipe the area around the popped area. Then apply a small amount of antibacterial cream on it, and you are done! The cream will prevent bacteria to enter the fishes body where the opening of the sac is. The fish can go back into his tank now. If a bit from the cream should come off in the tank, don't worry, it doesn't harm the fish at all.
Having medicated food around and feed it to the fish for 14 days is not a bad idea either. You can get a very good brand, Medigold, from Goldfishconnection.com. Or you can look at your local fish store for a product called Kanacyn, its also medicated, and all you have to do is soak your regular fish food in it for a few minutes and feed it to the fish. Prepare a new batch like that every day, don't use soaked food from the day befor.
Let us know how the fish is doing!....

when I got up this morning, the sac was popped (sac was clear). It looks like when you pop a blister, but almost back to normal. What caused the sac to grow is it bacteria, is that why my water is a light hazy white? I'm doin a water change tonight. I put some melafix in the tank last night, is that enough to kill the bacteria or should I use something stronger? Thanks for your help!

THe water being a slight haze does probably not come from the blister on the fish, its most likely something with the cycle of the filter. Maybe some meds took out some of the beneficial bacteria, and in order for them to reestablish, water will get hazy for a while. Its something people are concerned with and tend to hurry out and wonna do something about it, but the truth is, all you need is time, and some additional filter media in your filter. I use cheap polyester batting from the craft store for these cases.
The blister itself, well, it could be a few things that cause that. Something a simple as the fish ran into something spikey or sharp, like a rock, and ornament, even a spikey leaf of a plant. With a little opening like this, no matter how small, bacteria can enter, and cause a blister. Thats actually something I suspect, that he might have run into something, simply because the sac popped overnight - probably by getting penetrated by something in the tank again.
I have seen blisters like this associated with dropsy as well, but you didn't mention your fish having dropsy, so I don't think this is it. .....

As for doing something against the bacteria, there is bacteria in your tank at all times, and its perfectly fine, until the fish hurts himself or is weak from illness, and thats when bacteria gets into "attack" mood. Melafix surely doesn't hurt, and leaves the filter bacteria alone.

After I changed the water tonite, it has cleared up once again and he seems fine so I don't think I'm going to add anything else. I'll just make sure I monitor him and the tank really well for the next few days. Thanks for all your help!

You are welcome! Doing the least invasive method possible is always the best, in a lot of cases a water change and a bit salt will do. A lot of fish die because they are being overmedicated, so you did good with a water change and good water.

Keep us posted! ....