Back to the original question. Whether you use Prime or Amquel (which also reeks of sulphur) and NovAqua, you would benefit from letting the water sit for a while, even a long while, after treatment. I suggest getting a rubbermaid storage bin in the 24 gallon size and set it out of the way but near your tank. Measure 20 gallons of water into the bin and treat it. You can run an airstone or a powerhead in it to keep it stirred, or just let it sit. You could stick a heater to a piece of glass and set it in the bottom of the bin and keep the refill water at the same temp as your tank - stick one of those strip thermometers to the outside. There's your next 8 water changes, right there. Then refill and do it again. If you're situation is conducive to it, you can stick it on a mechanic's scooter, or just a board with four casters affixed, and then you can roll it to your tank and back to it's between water changes residence with the greatest of ease.