Ok, I was just looking at some of the guys bait tanks that they had set up at home, and I got an idea for one. I drew it up in google sketch so this is my idea. http://i267.photobucket.com/albums/ii310/chadrunge54/Baittank.png Hope it came up alright. So anyway, I am in the fish keeping hobby, so I know a little about keeping fish alive, and the biggest thing that is important to your fish is keeping the ammonia levels down, which can be done 1 of 2 ways, either chemically which in the long run can be expensive, or biologically, which is more expensive up front but will save you money in the long run, or you can spend a ton of time doing water changes every day to keep you fish healthy, which I dont know about you all but I have a lot of shit to do, and changing out water in your bait tank is a low proirity, but keeping bait alive o fish with another day is a high one. Now dont get me wrong, you will always have to do some water changes, probably once a week, to keep the nitrates down, I will explain. I would opt to go with the biological route, in my drawing you can see 2 large media tubs on the platform, these tubs are filled with something for the bacterai that will break down the fish waste into something less harmful to grow on. I have found that lava rock works great for a filter media, It has a large amount of surface area for the beneficial bacteria which breaks down amonia (fish waste). When you are keeping bait fish, many of you will be feeding them so they will grow larger, and stay healthy. The Fish eat, probably most the food, and the bi-product of this feeding is ammonia or nitrites in the water. These nitrites are very harmful to all fish and if not removed in some way will kill off your fish eventually. Like I said earlier you can remove these chemcially using soemthing that you can buy like shad saver, biologically, which is using bacteria in the media area to break these down, or they can be removed by doing frequent water changes. So I have opted to use the biological route, now remeber it takes a while for this bacteria to grow, so maybe just keep a few fish in your tank for the first few weeks, then you can add more until your tank has cycled (aquarium hobbiest term for you bait tank can handle a full load of fish and keep the water safe). Now When the bacteria breaks down the nitries it creates nitrates, which are less harmful to your fish, but left unchecked will still harm them, this is were your regualr water changes, i would suggest once a week, about 30% of your water, At this amount you wont have to worry about chlorine to much. The chlorine issue can be handled by putting water from your faucet into a container and leaving it set out for about a week, so when you do yur water chagnes jsut have a tub that hold the amount of water you exchange in you tank and fill it up agin before youleave, that way, no chlorine in your next water change. So anyway, this setup will keep your fish alive for a long time, hell, probably could breed goldfish in this setup. The reason I set my tank up this way is the bilge on one side, and the water being returned on the other,is so the wate will have some flow to it what you cant see is that the media tubs, have PVC going out the bottom through the plywood back into the tank, Now that I think of it I will post a reply to this thread, and show everyone how I would setup the media basket. Also with the tank, I would add a couple of areation device out in the middle just to make sure ecspecially if your tank is loaded with fish, that they are not getting shorted on air, though that is the good thing about these type of filters, they are called wet dry type of filter, and they expose the water to alot of air, helping with the air problem int he water. Hope this helps, maybe gives some of you an idea of what you can do to have a successful bait tank.