Backyard Aquaponics
A place to discuss aquaponics

I have 2 FTs each is about 275 gallons. I am thinking somewhere between 50-75 tilapia per FT, growing them to 2lbs each, so not sure if I should start with that many fingerlings, or more expecting the occasional... accident ?

Currently I have 2 GBs, one is more shallow about 12" the other is a bit deeper at about 18", and they are the top halfs of IBCs so about 4' x 4'.

In your collective expert opinion(s), how does that sound?

Thanks!

that's a bit overstocked..
25lbs grown out size for every 100 gallons of growbed should be the max in your system..
so to grow out 100lbs of fish, you should have at least 400 gallons of growbed volume

Hey gtmylo, I haven't read all of your thread yet, but judging by these last figures your giving I would be thinking a much lower stocking level like keith said. If you had them set up as 2 individual systems with the 275g tanks and 1 IBC half for a growbed on each system, you'd be looking at starting with about 10-15 fish per system, growing them out to about 1lb each. Maybe after your first batch you could look at increasing to about 15-20 fish a system.

But that's growing them to 1lb (500g) and allowing for the fact that it's a mature system..

thanks to all for the input!

Please also note that I am doing solids removal with a 55 gallon swirl filter before the growbeds, and then I have another 55 gallon suspended medium bio-filter that recirculates the water in the sump on a continuous basis...

With that in mind, any alterations on the above?

even with the added filtration.. i'd stock less, and let the system mature..
after you see how it does when you have some fish, you can add more..
come to think of it, tilapia are fairly easy to breed, so i'd definitely start with less

Told you I hadn't read your whole thread...

Yeah I'd still keep it low at least for a while so that you can monitor things.. Maybe 25% up on my previous recommendation.

After buying a pipe wrench, and using the full force of everything I had, I learned the hard way that screw-together PVC connectors do not fully screw together... at least not enough to tightly connect through the wall of an IBC... left about a quarter inch space when I expected it to seal tight. Put a bit of a roadblock up, so it took me a while to get to the solution.

I had to use a lot of silicone to seal everything, piped everything together, and used old metal coat hangers to support the pipes from the wall and roof beams. I then filled with water to test for leaks. A few leaks, re-sealed, and will try again tomorrow after the silicone dries. Here is what it looks like fully set up (water in the IBCs, had to drain the growbeds to re-seal standpipes):



I am hoping these seals hold so I can fully fill with water and fill the growbeds with the expanded clay... pretty sure I need at least another bag or two, and we are going by the hydroponics store tomorrow, so I hope to have everything re-tested in the AM so I can get the beds filled tomorrow and know how much more I need.

Once that is done, I will run the system a bit, get the water warm, plant the plants I have into the growbed, and transfer the 12 tilapia fingerlings into the tank.

Wish me luck!

Hey gtmylo, get elecrical conduit fittings (gray) from the electrical dept instead of plumbing fittings. The plumbing fittings are tapered and you run out of room before they seal thin plastic. Electrical conduit fittings are straight threads and you can tighten them all the way up. Don't know if they are wide enough for your pipes though.

Other folks may be able to tell you more about fittings for IBCs, bulkhead fittings might work although I don't know where to get those, and Uniseals are generally pretty great but you probably don't want to wait for a shipment of those.

Also, are you covering the IBCs with insulation? I had a bunch of leftover batt insulation and put that in garbage bags around my tanks and that worked well but was puffy and bulky-looking.

Wow, wish I had known about the conduit fittings before! Thanks for the info Dave! ...at this point I have everything to the point where it appears to not be leaking, so let's hope it sticks.

I do plan on insulating the tanks, I have similar rolled insulation, and I like the garbage bag idea... I ultimately plan on putting some sort of paneling around the outside so they look nice. I went to Lowes and could not find bulhead fittings, so I learned about the tapered PVC fittings the hard way!

Had to get an additional 5 50L bags of hydroton (after my original purchase of only 3), since I underestimated the amount of medium that would be required. Also had to lower the output valve on my swirl filter about 6 inches since it was too high, so when the silicone is dried on that in the morning, I will hopefully have a fully sealed and ready to plant system!

Any news? How is it going?

Thanks for checkin in ZsaZsa...

All has been set up and full of water. I still have to go through and rinse 5 more bags of hydroton, but the problem is my pump died ... it was not cheap at all, it was a Little Giant FP3, and I had turned it on the first time as a test, but after the second time I turned it on, it would not lift water! When I called them they said they rarely get calls on that pump and thought it was very strange.

Sooooooooooo, I am waiting for the replacement pump. My 12 tilapia that I got as a starter/test set are still hanging out in a 55 gallon aquarium, and I expect my breeder colony from Florida perhaps next week.

That's all for now! Will have another update (hopefully) soon!

If you dont mind me asking, what is your source for tilapia breeders? I remember coming across the site that sells the 2 different strains together but cant recall where it was. thanks!

http://tilapiafarmingathome.com/ - Edgar is a great guy, and he ships internationally! A breeder colony is 1 O Honorom male and 6 O Mobassica females, and when bred together they produce almost 100% males, so you have a very controlled environment, and the males grow much faster and bigger.

Actually, research by accredited universities has shown that pure Aureus and pure Niloticus outperform the Mossambicus x Hornorum hybrid.

Good to know, thanks for the info! As I grow my system I also plan to expand my lines... Do they also produce male-only offspring?