Originally Posted by Perseusmom
Prime only lasts for 48 hours so after that you need to add more for the whole tank. Like with my 5 gallon after 48 hours I will add 10 drops of Prime in some water and add to the tank to treat the entire tank. I have live plants too with a cycled tank and do a once a week 50 percent water change.
If your tank is properly cycled there is no need to add Prime other than to new water for a water change or when adding water to top off the tank. In a properly cycled tank there won't be any ammonia or nitrItes & the Prime will be used to make the new water safe by dechorinating it, removing heavy metals, or possibly detoxing the taps ammonia, nitrites or nitrates.