• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Feeder Tank


Oct 11, 2007
I want to set up a couple feeder tanks, one for shrimp, and another for Fiddler crabs. I am planning on, unless otherwise advised feeding one feeder shrimp (from Brine & Ghost Shrimp, Feeder Fish, Aquarium Supply - Live Brine Shrimp about halfway down the main page) and one crab a week as a treat. Does this sound reasonable?

And so forth I want to set up a tank for each. Possible a 2.5 gallon for 10 crabs, one a week. With a couple inches of water and sand so they can come out. And maybe a rock. Is that big enough, or should i shoot for a 5 gallon?

And then another 5 gallon tank, with a hang on filter and a bubbler for 100 shrimp. Again is that to small. If you want to see the size of the shrimp, here is a picture of them next to ruler.

usually with my feeder set-ups i go for more size, so there is less loss due to lower stress levels, and so i can see what food is leftover so i can siphon it out (bare bottom setups stay cleaner)
If it was me, 5 gallons is perfect for 10-20 crabs, and probably a 10-20 gallon for the shrimp. other than that, give your feeders good feed, and it becomes a nutritious snack :smile:
What size is your main system? If large enough and with good filtration, it is much easier to plumb in a small section.

I have a 2 gallon setup attached to my 150 that houses up to 250 marine shrimp, which is what you have in the link.

Ive kept crabs in small containers with shallow water and then rocks. A 2.5 can work, but you need to be careful with changing the water if you are going to keep the same crabs for a period of longer then a week. Just one crab dying can lead to all of them dying within a day. As mentioned, the larger th water volume, the less you need to worry.
My setup is 60 gallons with 100 pound of lr. So a 5 gal. would be enough for 100 shrimp? And since you've had some experience with these shrimp how many a day would an average sized octo eat? and are they suitable for small octo's?

thanks, ryan
I plumb my feeder bins into the main system--it makes life so much easier. This is a 3 or a 4 gallon plastic storage bin from Home Depot. Cut a hole in it for a 3/4" or 1/2" bulkhead. For crabs you can just put a strainer and some sand on the inside, then run a hose from the outside of the bulkhead into your sump. Water comes in via the air hose, fed from the sump by an Aqualifter pump or from the overflow via siphon action. I also like to throw a few PVC fittings in there because the crabs like to crawl under things--just be careful they can't climb out.

I use a similar arrangement for P. vulgaris. Since you want the water deeper I put an elbow and a length of PVC on the inside of the bulkhead to act as a standpipe. Use a rubber band and some fiberglass window screen to keep the shrimp from going in. The shrimp are great because they eat fish food.

nvm, i figured out what i want to do. i just need to make sure that 100 shrimp isn't too much of a load on a 5 gallon tank.
I put my shrimp in a large cooler with about 2 inches of water. No filtration, no heater, just salt water and fed them flake food. The large surface area allowed for oxygen transport from the air. The cooler was about 1.5 feet by 3.5 feet.
The shrimp I throw in the sumps always do much better than those in my crowded 10 gallons so if you can plumb through your system, that would be the way to go. Otherwise, if you can arrange for a 10 gallon for the shrimp (I use a 2 gallon with rocks to climb out of the water for 20 small fiddler crabs monthly) you will likely have better success keeping the shrimp healthy (a lot depends upon the time of the year). I use a nano hang on filter for the crabs (and almost never have losses) and a much larger hang on for the shrimp in a 10 gallons (I keep two and put roughly 250 in each).

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.