Based on what you've indicated, your tank is not cycled. If you are seeing
ammonia with no nitrates then you have not gone all the way through. The best thing to do is get a water treatment called "Prime". Use this each time you do your water changes. Treat only the clean water you are putting back into the tank. This will neutralize the toxic effect of the ammonia and nitrites in the tank and allow the fish to deal with the stress of the cycle. I also wouldn't add any more fish yet. I recommend you discontinue the pH
buffer unless your pH is way out of whack. Most fish will be able to adjust to the pH level of your tank naturally. What happens when using buffers is you tend to get spikes and dips in the pH which is far worse for the fish than say a slightly elevated or lower constant pH level. The fish will be lessed stressed without the pH spikes and dips. Have you tested your pH out of the tap? If not, get a glass of water from the tap and let it set out for 24hrs. Then test and record your pH level. That should give you a good base.
Next, if you can afford to do so, buy yourself an Aquarium Pharmaceuticals Freshwater Master
test kit. It is a liquid based kit that is far more accurate than test strips. Test strips though convenient are notoriously inaccurate and expensive. You can get the
API kit on line at PetSmart.com and from what I understand, if you print the ad with the price, they will honor that price in the stores. I think you can get them for around $20....But they are worth it and will last you fairly long.
As the cycle goes you will see an ammonia spike, followed by a spike in Nitrites....As the nitrites rise, the ammonia will fall back to zero....Then you should begin to see Nitrates...By then the nitrites should begin to fall and eventually drop back to zero....When all you a re seeing are Nitrates, the tank is cycled....Do a fairly large
water change and you can add a few more fish. Nitrates, while not as toxic as the other two, can still harm fish. This is one reason why we do regular water changes. To keep the nitrates below 20 and to maintain water quality as close to natural as possible. I do a 30% change once a week. You don't necessarily have to vacuum the tank until after the cycle. You are only prolonging the process. If you do wish to vacuum, vacuum no more than 1/3 of the gravel per week and do not change your filter media during the cycle period....Good luck and let us know how you're making out!!