ABOVE GROUND POND / TANK (load bearing question)

[Waterbug]

The main reason for the OSB beams is because I got a lot of it off Craig's List for a garage which I don't think I'm going to build now.

The pond on the roof would be to grow duck weed to feed tilapia. I'm already going to use EPDM for the roof so I figure I'd see how a duck weed roof would work. Here in the desert we can really do a live green roof, so I'll try duck weed. I'll have to test it first to see if it can even take full sun here.

This will be for just a 200 sq ft shop so not too big a risk. I think I'm going to have to build a beam and test its limit myself. I can calculate some things, but there's no data I can fine for this exact beam because I guess who would be dumb enough to do this? I guess worst case I can always add a steel beam later mid span if needed. Or add a column.

 

[Catfishnut]

Ah, a duck weed / talapia farm pond or hydroponics system. Sounds like a plan. Are you raising the talapia for sale, for your own use or a little of both? Or is it just simply an experiment for the sake of knowledge?

One thing that I would like to entertain in the future, beyond raising (or just keeping bait fish alive) would be a crawdad or shrimp farm. I have two of these large poly tanks (9.5' x 5.5' x 29"). One is my live bait fish pond and the other I don't know what to do with just yet.

My first notion was to use it as a river touring tank. People do that a lot here in Nebraska. They use a stock watering tank and install bench seats in it and then float down the river and have a blast. They call it "tanking".
I went through a lot of boat facts and engineering calculations to determine how many people and how many coolers and seating materials and what not you could have (by weight) to determine the draft of the tank so I'd know how deep the water had to be to float it. Our local rivers, except the Missouri, are generally pretty shallow with many sandbars, so you don't want to have to get out and portage this heavy tank very often! You'd need a few people to heft this tank, w/o anything in it. 25 years ago, this would have been an awesome adventure for my crowd and I.

Catfishnut

 

[Waterbug]

The talapia would be for my belly, but I guess I'm doing it mainly to learn something. I assume it'd be cheaper to just buy talapia from the store. That much I've already learned from DIY.

I'd really like to grow shrimp and we had a very long discussion about that on our local Phoenix permaculture forum. It's difficult getting stock, so not sure I ever will. But pulling huge shrimp out is appealing. I hadn't considered crawdads, but maybe I should look into that.

 

[Catfishnut]

Waterbug,

I like talapia, but I am really partial to walleye, flathead catfish and freshwater drum. These three fish have the absolute best taste for my pallet.

I think crawdads (or crayfish / mudbugs as they are often called) would be a lot easier to raise than shrimp. My Dad, after he retired and before he passed away, was really excited about such a venture. He was looking into land to purchase and how to go about setting up the ponds and all. He never did get there, though. His health went poor on him and he was gone before he had the opportunity to even test anything.

My Dad was looking at it from a monetary investment viewpoint. I look at these things, and I think you do too, as a challenge and an education and a hobby. I am not trying to make any money (and what I pay out to educate myself in these ventures proves it), but you never know what you might stumble upon for the future. Irregardless, it keeps my mind occupied and gives me a sense of escape from the humdrum of the regular life and work cycle.

Catfishnut

 

[Waterbug]

Talapia sure isn't at the top of my list either. It's good, but yeah, walleye, any catfish or bullhead would be higher. Yellow Perch, Striped Bass, really any bass, any salmon, any trout, on and on. But I can grow talapia. Although I'll try some catfish too if I can catch some.

I also do these things to learn. In college I had to take English Lit, Art, and a bunch of other classes not directly related to my major, Computer Sci. I think those unrelated classes have helped me in programming and I think learning about obscure things like ponds is just a continuation of that.