I would try Tex Gal's idea of adding more Prime, makes sense you may just need to use more. The bad part about that is you cant effectively test it with a kit, you would have to go off fish response. I have been thinking about this and I really dont think your problem is ammonia. The 1ppm out of your tap along with a sizeable dose in each of your buckets should certainly do the trick. Also, NH3-N or ammonia-nitrogen, is less toxic at lower ph levels where it is un-ionized NH3. As ph climbs its toxicity increases as it is now in an ionized form, NH4+. To add to that, temperature climbs also make ammonia more toxic. That being said, you may want to turn your attention to Heavy Metals in your water. I was curious about this in my water about a year ago and had someone from the water company come out and test my water. What followed was mind boggling! The levels of heavy metals from my sink, where I temp match the water, meaning some comes from the water heater, where at levels that no practical dose of prime would neutralize. Now the water from the outside garden hose faucet showed very manageable levels of heavy metals. Suffice it to say I now use the garden hose! Yes, there is a decent temp change and I have never noticed ill effects on the fish. I believe the temp change is FAR less taxing for them than massive amounts of Heavy Metals that I cannot fully neutralize. Thanks for reading, My rant is now over!