Original post made by Merle South(Slim) on December 9, 2003 As I was setting around Looking at my new bait tank setup I was thinking about filtration and how many guys are just at a loss when it comes down to how to keep your bait alive at home for long periods of time. I worked in the pet industry for years , a major pet store chain spent quite a bit of money teaching me how to keep fish alive and happy, I've even managed the aquatics department for a while. Anyway heres a simple filter design for the home bait tank ; First let's look at what kills fish. When fish "breath" they produce ammonia through their gills as well as when they defecate, ammonia is toxic to fish. Other things like rotting food and dead and decaying fish also produce toxins in your water. So what we need to do is get rid of the ammonia and filter out the chunks. When ammonia is present in the water, certain bacteria develop that turn ammonia into nitrites, which in turn decay into nitrates, which are not as toxic to your fish. What I have found is a simple wet--dry filtration system can keep your bait alive for as long as you keep them fed and meet their other environmental needs, ie temp and stress level. Now keep in mind that water flow is the key, water flow means a pump- you want the water to cycle roughly 4 times through your your entire tank an hour; for example, if your bait tank is 20gal, the pump should cycle 80gph(gallons per hour). I have seen people use swimming pool pumps, swamp cooler pumps, power heads from real aquarium setups, and many others, feel free to be creative. Now you need a filter box, someplace for the pump to sit and someplace for that bacteria to grow. I've used plastic storage bins from Wal-Mart. The pump sets in the bottom, with a return hose to the tank. You'll want enough space in the bottom for a sump so your pump won't run dry. Above the pump is a florescent light cover, the "grate" kind with about 50 plastic hair rollers sitting on top (yes those pink things that your mom used to wear at night so her hair would be nice the next day) that's called "bio media", and gives you someplace for your bacteria to grow. Then you want another florescent light cover on top. Cover that with a swamp cooler pad, the blue type, not the natural. On top of that place a floss filter material, you can buy that at most pet shops by the roll. Now to top this off you need a "drip plate" to spread the water out over your filter media. A plastic plate the size of the box with small holes drilled in it works fine. Now, how to get the water to the filter. A simple siphon works extremely well. The drain hose off a washer already has the bend in it to hang over the side of your tank. You will need to install a valve on it someplace to regulate the flow of water into your filter. Now you've got a working filter! Remember, that bacteria needs to develop so start slowly , depending on the size of the tank maybe 1 inch of fish for every 2 1/2 gallons of water, do a 50% water change once a week for the first 3 weeks then cut back to 25% for 3 weeks then 25% every other week. Into the 5th week you can double the amount of fish and after the6th or seventh week you can add 25 percent more again, always leave some fish in there to keep feeding your bacteria. I toss a bubbler in the bottom of mine to help keep the crap floating to my intake tube. Some people use "sprayers" on their return hoses but I've found that just the inlet pouring into the tank work just fine. Good luck!