As you PM'd me, I have reviewed the last couple of pages with respect to the ammonia issue. This is not as bad as it might seem at first; of the three nitrogen issues (ammonia, nitrite and nitrate) that might occur in tap water, ammonia is the easiest and frankly safest to handle.
I would not reduce the volume at water changes and go with more. All you need to do is deal with the initial influx of ammonia, for the first 24 hours; after that, the live plants and bacteria will easily deal with it. Especially in this minimal amount.
I would use a water conditioner that detoxifies ammonia, but not Prime. Sorry, but this product simply does too much that is unnecessary in a healthy tank where nature should be dealing with things. The extra TDS added to the water does affect fish, notwithstanding what Seachem may like to tell us. There are several conditioners that detoxify ammonia, any one will do fine. All of them as far as I know detoxify ammonia by changing it to ammonium; plants and bacteria will take this up readily.
The initial 24 hours is the key. Nitrosomonas bacteria will multiply in about 9 hours if ammonia increases. And live plants will take it up very quickly. I don't have specific amounts or time periods, but when I raised this very issue with Tom Barr he said there would almost never be an issue over ammonia in a fairly well-planted tank because the plants can grab so much of it. For all I know, the ammonia-detoxifying conditioner may be unnecessary for this reason, but using one is not going to do any harm.