Hanging Demand Feeder for fish

DanDMan

From: http://rps.uvi.edu/AES/Aquaculture/fishfeed.html

http://rps.uvi.edu/AES/Aquaculture/fishfeed.html wrote:

Each fish rearing tank is supplied with a hanging demand feeder. A demand feeder is activated by the fish when hungry. It consists of a feed hopper having a hole on the bottom with a control plate and rod. The control plate is adjusted to the width of a feed pellet and keeps feed from pouring out of the hole. A rod connected inside the hopper and through the hole and the center of the control plate extends down and into the water. The feeder holds 50 lbs. of floating feed. When a fish is hungry it bumps the rod with its head and feed spills from the plate into the water. The fish can then eat. The fish learn to do this in about 3 days. The control plate can be adjusted to release feed easily during the training period. The manager can assist feeding by tapping the rod and releasing feed. Using demand feeders is a good practice. It reduces labor that would be needed if multiple feedings were scheduled throughout the day. Tilapia have a small stomach and long intestine and are better suited to eating many small meals rather than two or three large ones. Feed tables, growth rate charts and sampling are not needed. Finally, they do not overeat and feed conversion ratios are approximately the same for demand feeder and hand fed rearing.

I find this a very interesting idea. It theory it I have enough growbed for the amount of food the fish want to eat then I should be able to let them feed them selves. This would really help when I need to go out of town for a week or two! Cutting the amount of time I must attend the system is a plus also. Otherwise I have to depend on my children to feed the fish during the day; they will get to much to eat then.

Does anyone have any information on how these feeders work. I would like to build one.

janethesselberth

There is a certain danger that the fish would feed themselves more than your growbeds can handle. That would be my situation right now, as I have the fish on short rations. I am a bit overstocked. If you install one, I would use it while you are home for at least a week, and I would monitor food usage and water quality daily.

If you pre-measured the food for your children to administer, that should work fine.

I have seen rough diagrams for how these feeders work, but it took a lot of digging to find one.

I know they are designed to work with pellets, not flakes. So the fishies need to be a little bigger before you can use one.

DanDMan

So they are for big fish then. Ok, still I would like to try to build one for when they get older. BTW, how much should they be fed? Only as much as the ammonia stays low, or is there an amount per gram of fish?

janethesselberth

Feed lightly for the first few days to get them settled in, and to make sure your bacteria can keep up. Slowly increase feed to as much as they will eat in 10 minutes or so, 3x per day. Again, monitor ammonia so you can see that the bacteria is keeping up with you. If you get ammonia readings, cut back on the food until the ammonia resolves. On the assumption that the fish are somewhere under 5 grams in weight, you will be working your way up to 10-15% of their body weight in food each day.

tamo42

You can also get those slow dissolving tablets if you are really intent on feeding them while you are away.

DanDMan

I can only be there to feed them twice a day. I could rig something to dump an tube of fish food at lunch. Then each day I could see how much they eat in the morning and put that amount into the tube for lunch time.

janethesselberth

Then feed twice a day. no problem. They'll eat what you give them, and pick at algae on the walls. You could also float spinach leaves on the water to give them 'time release' food. Or bean leaves or leaf lettuce. Whatever you have. The more you feed them, the faster they would grow, but nobody said you have to try to break speed records.

Food&Fish

Les has an auto feeder [hows that going]

EllKayBee

Quote:

Les has an auto feeder [hows that going]

This is the one I bought, I cut out the bottom of the tray and allow the pellets to slide straight into the tank - works well, I only use it when I am away for an extended period (days)
Auto Pet Feeder (for Fish)

If you want to build a feeder, here is one that can be converted to fish feeding
Fish Feeder Project

I am not a big fan of the demand feeder, there is no control over it

veggie boy

There is a thread here somewhere on this which includes links to a fish autofeeder building instruction. I checked it out ages ago and looked pretty easy to make. However I prefer the idea of using the per autofeeder like Les has so that the amount of food can be regulated.

Jaymie

when you have fish that are exuberant in their feeding, demand feeders will empty themselves in a matter of minutes :shock:

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Hanging Demand Feeder for fish

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