Hi 20GalNewbie,
Welcome to Aquarium Advice! I'm sorry to hear of your troubles with this tank. Unfortunately,
lfs don't explain cycling to first-time fish owners very well.
The seven days that you had your aquarium set up with no fish was just wasted time, unfortunately. Your cycle didn't start because you didn't have an ammonia source to start the cycle. Fish and their wastes produce ammonia to start the cycle, OR a lot of us do fishless cycling -- adding household ammonia to start the cycle so fish don't suffer during the cycle.
Read about the nitrogen cycle here:
http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=21
http://faq.thekrib.com/begin.html
In the last link, read especially under "Setting up your tank" and "Cycling your tank".
You should get test kits that are more accurate than the strip kits. Aquarium Pharmaceuticals makes a good test-tube type kit. The tests that you need are ammonia (get the kind with TWO test bottles), nitrite, and nitrate. Your pH of 7 is fine.
For the next week or two, you'll have to check your ammonia and nitrite levels daily. Do a 30 - 50% water change every day, depending on how high the levels are, to keep the ammonia and nitrite from killing the fish. Keep checking the parameters and when the nitrates show up, the tank is cycled. Can you find any freshwater Bio-Spira bacteria from Marineland? If so, use it, but you'll still need to check your parameters and do water changes as necessary. This product will cycle a tank in 2-3 days. It's meant to be added right when the fish are new, not later -- but it can help you out here by adding some good bacteria, so if you can find some, get it. Otherwise, you'll have to go through the cycle the long way -- a few weeks.
When you're changing the water, you can use Amquel as your dechlorinator. Use the amount specified on the bottle for initially treating your tapwater. I use about 6-7 drops per gallon. If you dose more often than the initial treatment, you'll be binding the ammonia away from the "good" bacteria that you want to cultivate. Remember, this bacteria needs the ammonia as its food source. Let the cycling process happen naturally, and do water changes to keep the levels healthy for the fish, and don't depend on a large dose of Amquel. Especially if you buy the Bio-Spira, and then add large doses of Amquel, you'll just be wasting the money you spent on the Bio-Spira! A large dose of Amquel will negate the Bio-Spira.
Also during the water change, try not to use your gravel vac too much. Leave the gravel undisturbed -- the gravel is where the bacteria will grow and live. You don't want to vac it out right away! If your ammonia reading is off the charts, then gravel vac about half the tank to get some of the wastes out. This may prolong the cycle but it's better for the fish to get that ammonia level down. Also during this time, don't rinse your filter media. This is also where the good bacteria will live and grow and you don't want to disturb this area either.
HTH!
