My ammonia level was as high as it gets! With the API test kit it was reading at 8ppm
The issue is that you are reading a combined ammonia/ammonium level with the API test so it may not be the cause of your problem. In fact, the optimal Ph for nitrification is 8.0 so I wouldn't have altered it.
One of the issues with the " Bacteria in a bottle" route is that you do not know whether the bacteria in the bottle is in fact still alive. Heat and cold can kill it while in route to you or the store. It could have been stored wrong and the bacteria died. The only way to know is if you get nitrates after you add ammonia. The only bacteria in a bottle I've used with great success has been the Fritz brand ( Fritzyme #7 for freshwater) and Fritzyme #9 (for saltwater tanks.) That said, with it being winter now, who knows if it arrives to you or the store alive. You are better off getting some filter material from an existing system so that you are inoculating your tank with live bacteria. Add an ammonia source at the same time as the filter material so that there is food for the microbes to feed off of. This is how you instantly "cycle" a tank. Without doing this, you are looking at weeks to months for it to happen naturally.
I should also stop here to explain what the cycle ( a.k.a. creating the biological filter) means: When you have a cycled tank, it means that you have enough microbes within the system to convert the amount of ammonia being produced by your ammonia source ( fish, snails, etc) into nitrates in under 24 hours. Now, let's use fish as an example: Say you added 2 small fish and the ammonia level rose and then went back to 0 and your nitrite level rose and went back to 0 and your nitrate level has started to rise, it means that your tank is cycled for those 2 small fish and so every time you add more fish, the amount of microbes needs to grow to handle the extra ammonia being produced. Now let's say you added 1 large fish to start the tank instead of the 2 small ones. Once your ammonia and nitrite levels rose and then went back to 0 you have a cycled tank for 1 large fish (or a number of small fish if you remove the large fish ) that will equal the amount of ammonia that 1 large fish was producing. Here's the thing about the biological filter, it's a living breathing thing that grows and shrinks to the amount of ammonia present in the tank. So the reason people suggest using a higher amount of ammonia to " cycle" the tank is because it's usually a higher amount than most tanks will house full of fish. What will happen is some of the bacteria bed will die off from the reduction in ammonia. That is a safer route than adding fish and having the ammonia rise to a dangerous level while the bacteria bed grows.
So, with all that said, what I would do is go back to using your tap water without altering the Ph. Check the water for ammonia and record the result somewhere handy. Check your local water department's website or call them to find out if they add chloramine to the water and at what level. If they do, use a product like Seachem PRIME or other product that breaks the chlorine ammonia bond and then test ammonia again in about 30 minutes. Compare the result to the first test. You SHOULD have an ammonia reading coming from the ammonium created by the PRIME or other product. IF you do not get an ammonia level and your water company uses Chloramine, you need to have your test reagents checked to confirm they are accurate or not expired.
Let's start with this and go from there.