I have an Alumacraft 1670LW. The live well has no aerator and I want to fish some winter tournaments out of it. What do you all use to keep your fish alive?

First you will need to see what the tournament rules require.  Some get pretty specific about what's required.   They want to make sure the fish has every chance to survive being hauled around several hours and released.

You can either plumb one in or get one of those that work in a cooler and adapt it to it. 

It's main function is to recirculate the water that's in the live well by sucking it up and spray it through the air back onto the surface, increasing the waters surface contact area with the air so it can pick up more oxygen.  Chemicals are sometimes added to the water to help calm the fish, make it re-slime itself and the water hold more oxygen.

Built in system will usually also have the ability to do water changes by pulling in lake water and letting the excess overflow back into the lake.  This feature you probably won't have unless you want to drill holes in the hull and install a permanent, full blown system.   If you are adding chemicals, you also don't want to use this because you flush them out fairly quickly. 

Sounds like I want a reciculator. I have a bulge pump that runs off a small 12v battery. I use it on rainy days to pump water out of my boat, but maybe I can use it as a recirculator as well.

If it's submersible.  Just drop a submersible pump in one corner of the bottom with a piece of PVC pipe coming up and into an elbow.  Cut several small slits or drill some holes (start small and you can increase to what gives the best action) and cap off the end in another piece of PVC a couple inches or so above the water level going across the back on down one side and connect it to the elbow.    Be sure to put one of the wire mesh screens over the input of the pump, if not you can bet a fishes tail will keep it blocked up most of the time.

The next item needed will be some sort of timer you can adjust the on/off run cycle.  If you just let it run, it can put too much oxygen in the water and that can harm the fish.  The timers are not very expensive.  You can buy them that are preset and just a small module, or you can buy them with a switch to change between auto and manual and adjust the on/off time.  Naturally, the more flexibility you get, the more it will cost.

Add a aeration pump. 1/2" PVC tubing with T valve fitting  that you close to pump water through the tubing and open to pump water out of the cooler. Drill 1/8" dia holes in the tubing and a end cap. Use adhesive plastic ties to hold the tubing to the inside of the livewell. You will need a power toggle switch to run the pump. I believe cooler aeration kits are availble on the market now, I made mine. You bucket the water in and pump it out.

Tom

You can buy these cooler live well aerator kits that include the pump, tubing and pvc pipe.