I would do another pwc today--50%. For that size tank a python would work but is unnecessary IMO. I would just use a small gravel vac/siphon.
As far as temp, try and get it to within 1-2 degrees. The human hand is good at determining temp. Just stick your hand in the tank and then under the faucet and try and get close. I have never even checked the temp with a thermometer while doing pwcs and I always just add the water straight away (after adding prime of course!).
From what I've come to understand there's a couple things better about prime:
-Prime neutralizes ammonia. It also states it detoxifies nitrite and nitrate also. This is temporary, but can be helpful while cycling with fish if used during daily PWCs.
-It's more concentrated, it treats more water. In a 100ml bottle: TetraAqua AquaSafe Plus treats 200 gallons, Prime treats 1000.
no. The ammonia is still present, and still a food source for the nitrobacter bacteria. The prime helps to neutralize it, but it is still there.
I use prime though because of the fact that is far more concentrated than other products... so like was said above, the same amount of prime treats many times as many gallons as the same amount of most other dechlorinators.
I would skip the catfish in a 10gal tank.
Once the tank is cycled, I would get a school of 10 neons or 8 zebra danios to add into the tank. They are more interesting to watch when they are kept in larger groups. Danios are more hardy - neons can be sensitive to water quality... although not difficult to care for if you keep up with PWCs.
+1 to all of this.
however, to be honest, i do not quarantine my fish. i do not have hundreds of dollars invested in my fish, so i understand that by not QTing, i run the risk of introducing any disease new fish may be carrying and possibly losing my whole tank. i am aware of this, and, knock on wood, i have not had any problems yet. with a 10gallon tank i think it is a little silly to QT all your fish (unless you KNOW it is diseased) since you have minimal stock anyway. but that is just my 2 cents
i also test temp by hand feel. never have used a thermometer before adding water to the tank. if it is a couple of degrees off it's no biggy, the water that is already in the tank and the heater will both work to even it out.
i think Prime is so recommended around the site (and other sites) because of it's value. it may cost a couple more bucks up front, but will last 5 times as long. it's worth it. also, it will not counter act the nitrogen cycle, whether the Prime neutralizes or not, your fish will always produce ammonia (as well as any left over food) so there will always be a food source for the bacteria as long as there is an ammonia source.
i would also skip catfish, as any cat fish will be too large for your tank. check out otos, they're great algae eaters, stay nice and small, and when you have a group of them in your tank they are some of the most fun fish to watch. just keep in mind that they do prefer to be in groups, so if you have less than 4 they may not be so happy or active.
there are tons of fish that can live happily in a 10 gallon tank. there are TONS of varieties of tetra (which are my favorite). tetras should not be added until your tank is fully cycled however, because they are sensitive to water conditions (like said above, as long as you keep up with weekly PWC's after you are cycled, it's quite easy to accomplish.)
i myself have ember tetras, glowlight tetras, cardinal tetras, and black neon tetras. i also like von rio tetras, cochu's blue tetras, lemon tetras, albino black neon tetras, and penguin tetras.
of the ones above, embers are the smallest. you could get away with 12 easily in a 10 gallon.
there are also dwarf gourami's that you could get in a 10gal, but i have not had luck with them myself. they are very prone to disease and don't usually last long in an aquarium. i have had a flame dwarf gourami and a flamingo gourami, both lasted less than a few months. i know sparkling gouramis stay nice and small, but i don't have any personal experience with them.