Hi, and welcome to the AA forum.
I, also, have well water, and have had many questions with regard to it. My daughter had a small freshwater tank for almost 4 years, and the water was always tan to brown, so she quit using tap water, and bought spring water at the store for pwc
's. Last summer she bought a slightly larger tank which I ended up setting up and taking over cause she had so little time. So, since I knew nothing about freshwater fish or freshwater fishkeeping, I began to research, found this forum, and discovered fishless cycling, API liquid test kits, etc. I have researched at great length, the issue of well water, and to the best of my knowledge, it seems that the worst problem I have is in regards to the amount of dissolved carbonates and other minerals, and that the pH is a tad on the high side, from usually 7.6 but sometimes as high as 8.4. Don't know what causes the occasional spike, but then again, Texas has been under the worst drought in its recorded history this year. That may have some bearing on it.
So...that said, IMO
, I think it is very strange that you have no nitRATES, and, in any case, BB's would have little effect on your trates. Perhaps, your tank hasn't really cycled yet. Maybe, the ammo load on your tank is too small, so you haven't been able to get the ammo spike, followed by the niTRITE spike, which would then both drop to 0, as I'm sure you already know. I'm just thinking out loud, here. Could you throw some extra fish food, or a shrimp in to start an ammo surge, and see if your filters can convert it?
Anyway, it's a very interesting challenge, and I hope you find the answer soon. But I DO think well water is very good for African Cichlids, since they like alkalotic, hard water. Something to think about, when you get this cycle issue resoved. Have fun with your son. I have a 5 year old granddaughter who helps me with her mommy's tank. She loves it.
Sorry to be so long winded. Promise I won't do it again.