Backyard Aquaponics
A place to discuss aquaponics

Well, what size is the plumbing from your pump? Always start from there.

Then make the plumbing from your fish tank to the grow beds a couple sizes larger because gravity flow isn't as strong.

Kuda is right that the shallow bins might be near the line for fish tank and sump tank. The tricky part is going to be that your pump probably can't suck water down more than a few inches from the bottom so you kinda loose some of your sump capacity. The grow beds need about 40% of their volume in water to fill them up so added together that would be 80% of the sump capacity. 20% in the bottom of the sump might be pretty near where the pump starts sucking air. In order to make this all work, you might not want to fill the grow beds as full so that flooding to a couple cm below the surface of the gravel won't use as much water. I would recommend using loop siphons from the grow beds to make it easier to adjust the flood level to get it tweeked just right for your situation.

I would probably make the loop syphons out of the same size tubing as you use for the pump if it is flexible enough to make a loop without flattening too much.

Here is a thread that you might find useful to read since she wound up using some of those tubs as grow beds.
http://backyardaquaponics.com/forum/viewtopic.php?f=18&t=735&st=0&sk=t&sd=a
this like will take you to the beginning of her thread if you want to read through the whole process which I do kinda recommend newbies pick a few of the big long threads to go through just so they have a chance to learn from other people's mistakes rather than having to make them all themselves.

Here is a post that shows a picture of how she has the plumbing hooked up.
http://backyardaquaponics.com/forum/viewtopic.php?p=35229#p35229


Do your tubs have a drain fitting on the side near the bottom? If so, you might be able to use those fittings and avoid having to buy bulkhead fittings or drilling any holes for the primary plumbing though I still recommend adding some overflows up near the top edge but I know those can sometimes be managed by drilling just the right size hole and screwing in a threaded fitting with a little aquarium silicone.

About avoiding leaks, depending on your pump plumbing, you might get away without using much in the way of glue since the rest of your system will only be under gravity pressure. Thread tape and a bit of aquarium silicone might be all you will need. I've only glued where I'm under pressure or where I find leaking.

I just found a good deal on a 180 gallon acrylic tank with an overflow $40. If I bought it would I use it for an FT? Would I be able to grow edible fish?

Any chance of a picture.

dunno if its going to to through yet. might have jumped the gun.