My mom bought me 5 new fish a few days ago. They were seeming pretty good. Then today while I was watching them eat, at least two of them have fins that look a little jagged. I can't see any streaks or flashing and they are eating well. I wasn't able to QT them because they were in the tank when I got home and my 20 gal is on loan.

Test Results for the Following:
Ammonia Level? 0.25 (still cycling)
Nitrite Level? 0
Nitrate level? 0
Ph Level, (If possible,KH and GH and chloramines)? 7.8
Ph Level out of the Tap? 7.6
Tank size (How many Gals) and How long has it been running? 90, 3-4 weeks
What is the name and size of the filter/s? Magnum 350 and AquaClear 110
How often do you change the water and how much? Once a week, 20%
How many fish in the tank and their size? 9, 1-3"
What kind of water additives or conditioners? Aqua Plus
Any medications added to the tank? No
Add any new fish to the tank? Yes, 2 that just came out of QT and 5 straight from the store
What do you feed your fish? Omega One, peas, oranges, algae discs, bloodworms
Any unusual findings on the fish such as "grains of salt", bloody streaks, frayed fins or fungus? Jagged Fins. The moor had a red mark under his eye (a bruise I assume) but it has since dissapeared
Any unusual behavior like staying at the bottom, not eating, ect..? No

Maybe you should just treat the whole tank for parasites. Do a 75% water change. Buy some canning and pickling salt from the supermarket.
Add 1 teaspoon per gallon. Wait 12 Hours and add another teaspoon per gallon, Twelve hours later add another teaspoon per gallon. Which will
bring you up to the medicine dosage. You must also dissove the salt before you add it to the tank. I use a cup with tank water and a plastic spoon to
stir it.
We'll see what one of the mods think

Does anyone have any other ideas? I took the two out that looked bad and got my 20 gal back. I noticed a single red streak in the fin of one of them.