What are the readings after the water conditioner? If your TDS is much higher, I suspect sodium (unless you use potassium in your softener).
Based upon previous threads, I would bypass the water softener and use your tap water. Your readings are very similar to mine and my discus are doing great!
Now is you want to breed your discus, I would use RO after the softener. Since you would only be removing the sodium, your RO membrane would last a very long time...