Backyard Aquaponics
A place to discuss aquaponics

Thinking of using a 500 gallon spa, and a 200 gallon plastic pre formed garden pond as a new tilapia tank. The idea is to put the spa above ground with access to bottom drain, for solids removal. Will set the small pool on top of spa, pump from spa to pool and then overflow into spa. Want to do this on the "cheap", so any suggestions are welcome. I'm looking for a light, effective media choice. Plastic balls? Rock is going to be very heavy, but is an option. I'm not concerned about the plant growth for this one. Will end up putting in something to consume nitrates at some point. Really working on the fish aspect, trying to make them cozy, and get them growing, breeding and happy. I have some tanks set up as well, once I get the bulk moved into the spa, will concentrate on getting them breeding. Looking to have a supply to replace my harvested fish...which will be ready soon. Anyone ever get attached after 8-9 months and start pondering keeping their dinner? I've spent more time with them then I ever did with any other animals raised for food. At least I haven't named them.lol

probably need to support the base of the GB, even with light media 200 gallons (US) of water is goner be maybe 700kg,.

can you build a base from blocks or such and put it next to the FT?

Your right SB. I plan on using some braces to support on edges of spa. 4 x 4 landscape timbers most likely. Have access to aluminum tubing also, but i can't weld it, so would have to drill and screw. prefer the chainsaw & skill saw.lol

Bio balls are very good cheapish and efficient, how about Pumice Stone it's an inert volcanic rock very very light and it floats until it soaks up water,it is also said to give up some of it's minerals back into solution so it's meant to be good for growing. I still have one bed full of it,I had it left over from the Koi Pond filter.

DB, I've thought of Bio-balls, but can't find a cheap source here. They want 25.00 for a small bag, and when I did a "wholesale" search, I got $300.00 plus for 4 cu ft. I figured I need 3-4x that. Haven't measured the pond yet, but just an estimate. Any sources state side? My brother-in-law is in the plastics industry, so I have him looking for something cheap.

Bit of an outlandish one but i know it works as i have used in the past,not as all of the media but in one chamber and thats the plastic strapping they use to secure parcels.It comes in large rolls and has a dimpled surface to make there clamps efficient,stops them slipping and also helps for the bacteria to cling on, you pull it from the spool scrunch it up and put in the filter chamber,you do need to place something on top of it just to hold it down,but as a bio media it does work and as you said your not worried about planting maybe worth looking at.

That's an idea. Did you band it, or just kind of wad it up? Seems like it would be bit tough to work with without some sort of restraint?? Hopefully my bro in law will find some nice scrap pieces free or cheap that I can just dump in. What do people use to keep them from floating? Or is it not an issue? Thinking they may end up pushing out of my plastic pond, since it is much wider then deep.

Thinking outside the box - Since you prefer chainsaws and skilsaws... Take a plastic barrel and slice it up! They are slightly buoyant (maybe 99.999% the density of water) so you may need to strap them all together or put something on top. Once you cut up 2 or 3 barrels to stuff in the volume of one barrel, you've got a lot of surface area. I think a skilsaw would give you the least waste, unless you want to put all the really fine shavings into your system. (stick in a mesh bag?) On the plus side, it would not be any heavier than the water. And around here, I can get all the barrels I want for free from car wash places.

LJS- that might work, just thinking that there's not a lot of surface area on that smooth plastic. Another option could be netting or geotextile fabric. I think the UVI system uses something like that. 2 different pieces, they rotate them in and out and clean them daily. They have a lot of fish...I probably would need to clean mine that often. I'm tearing out some ol;d fabric in the nursery...might try it. Will need to weigh in down with some large rocks or brick or something. Then I'll throw in some airstones and let it overflow back into the FT. Figure on making a few wicking beds for when I need to do water changes. Don't want to waste that good fish poo.lol