Do not be afraid to use ice but try to use non-chlorine ice if you can, primarily this is done by making your own ice. Also do some research on additives I believe "Fish O2" is the best on the market because it removes almost all harmful chemicals out of your livewell water. Change your water out and add ice you will hear allot of guys that use the frozen bottle method which is also great. Search youtube for video's on hydrogen peroxide use in live wells by Doug Hannon (the bass professor) it's very informative.