Fish (trout) in a Barrel

[Eric Warwick]

Today I just bought a 50 gallon (189L) barrel for a system that will probably be a mixed system, with media (red lava rock) and deep water culture. The deep water culture will be the sump. Anyways you can answer my question, without having to look further by answering this: can trout survive well in a 50 gallon barrel? 

I live in an area where summers are usually in the 70's with days in the 60's and sometimes 90's. Also the winters rarely have frosts with temperatures in the 40's normally, but sometimes with week long stretches of sub-freezing temperatures. The coldest day had a low temperature at 9f. I'm not worried about rainbow trout in the winter, but the summer might be an issue.

Since Summer is just around the corner I was thinking of starting with goldfish. 

Just to keep everything in a tidy thread I have a few more question--if you don't mind.

1. How much aeration should I have?

2. At what concentration should I worry about the trouts well being?

3. I will be away from the system for at least 3 days at a time, should I have an automatic feeder?

4. If so, should I have automatic testing (I'll ask the automation group about this if it is recommended)?

5. What is an appropriate harvest size?

6. How can you kill trout humanely? (I have a few ideas--they include cutting it around a vein along the "neck"."

7. Should I get a dissolved oxygen monitor?

8. Will they eat insects if they're "spoiled" with pelleted food? (This happened with tilapia.)

Thank you. 

[Tom OBrien]

I'm not an expert, but I've been keeping some trout alive in two separate 150 gallon stock tanks for about 5 weeks now, so my experience may be applicable. I started with just 25 fish and bought them as 6-8 inch fingerlings. I've had some losses. Some fish jumped out before we got the cover on, and several went belly up so we are now down to 15. I think the smaller the tank, the more likely you are to have trouble so starting up with fishless cycling and getting plants in before you get the trout is a good idea. I have a couple air pumps going, but I didn't buy a test kit for DO so I'm not sure if I have enough but the survivors seem happy now. I've had some insects get under the covers and the fish do seem to go after them sometimes, so they may still eat bugs even if you feed them pellets.

[Cai Robertson]

It is recommend to have at least 300 gallons of tank for a stable system. There is someone on here that successfully raised rainbow trout in water that would reach 80 degrees but that was pushing their luck. I have been thinking about rainbows for my system with a large in-ground tank, just north of Toronto, but I am thinking I will run the system for the first year with black crappie as they are very tasty and highly adaptave to a variety of conditions. If the temps are reasonable through the summer I will give the rainbows a try. As the temps rise DO levels drop, so the higher your average temps, the more aeration you will need.

[Eric Warwick]

For #2 I meant concentration of NO3. Thank you for responding. I have experience with tilapia, but none with trout, so this is very helpful.

@Cai: I know I should have a larger system, but I don't have the space or the expertise to do it.