Backyard Aquaponics
A place to discuss aquaponics

Hi All. Firstly thanks for all the help I have received to this point. It really helps. I have some photos of my system progress. And of course it wouldn't be complete without a question or two.

You will see that I have one GB above the FT and one GB sitting on stands considerably lower. {All need to be levelled and pebbles put in place etc yet.} the other FT is to be a sump and maybe later another FT. There is a black barrel (250L) in the back ground collecting rainwater and a backup water supply or maybe even a yabbie holding bin, or a quarantine tank??) I got my new 3500 LPH pump a week ago so I have just been working the water over in the black barrel.

Any way the question is how will the GB at the lower level pump water from a drain back to the FT? Obviously gravity wont work so what do I do there? I did think I could run it through PVC along the ground to the outlet pipe of the sump? Any ideas please?

Coming together Rod

OzzyRod,

You are going to have to raise your growbed to allow it to drain back to your fish tank. Your only other option would be to install a sump under it and then a second pump (possibly on a float switch). Much simplier to raise the growbed.

I'd reinforce the left hand FT IBC frame (where you've cut the top "rail" off) and put the GB on top, and have two systems side-by-side, running as completely separate systems (recommended) or you could conjoin them if you wanted to (I wouldn't).

Also, on the right hand side GB, give the "spikes" of the frame something to sit on, then turn the frame up the other way so the rail is about 25-50mm below the lip of the GB; unnecessary spikes can be removed. There is almost no strength in the spikes when they're pointing skywards like shown and they will do little to stop the GB from bowing when filled with media, plants and water; with the frame up the other way, the rail will prevent the GB from bowing where the distortion is most evident i.e. near the top edge in the middle of each side.

A good reason why we draw plans first.... plan, plan and plan again, measure twice, cut once.

Missed the above... shouldn't skim read posts...

Ahh Thats why I post questions. I have made changes as described. Two FT two GB as seperates systems. BUt wouldnt I need more than one GB per system? If so where to go as I have limited space? New pics below show set up as suggested. My neighbour is going to weld a support around the GB that I cut in the wrong place so that should be fine.

All depends on how many fish u want to have. There is a formula but I can't remember what is is.

That will work better. You could either run two separate systems or link the two and have a large volume of water which will make somethings like pH and temperature more stable.

All you have to do is stock to the filtration (or growbed) capacity. If the beds are 300mm deep then you have 300 litres of filtration each - total of 600 litres so good for about 25 fish.

The formula mentioned by Thommoperth is 3kg of harvest size fish for every 100 litres of filtration. Assuming harvest size is 500 grams per fish that is 6 fish per 100 litres. These figures are for mature systems so best starting with less fish - you will get good growth from your veggies even with only 5 fish per tank.

The more grow beds you have... the more fish you can have... and/or the more plant you can grow...

Each of the (two) systems.. with a single grow bed.... will handle 10-15 (max) fish...

Thanks guys. I think I'll go one 900 liter system supporting the two grow beds to give me more fish in the long run. I'll use the second tank as the sump. But I'll not cut the plastic to join them, I'll use the taps at the bottom. That should work yeah? It should also give me what I've heard referred to as chift (constant height in fish tank) anyway it will be suck it and see what works for the first setup. I can't begin to tell you how addictive this all gets. But I have resisted the urge to rush ahead too quickly. I've still got landscaping, painting, electrical work to do

Joining the two tanks wont give you a chift pist system but it will stop the wate level from dropping as much. You could achieve a constant height in the fish tank, but would require two pumps - one in the fish tank pumping to the growbeds and another in the 'sump' tank keeping the height the same.

If you run constant flood your tank level wont change. If you run flood and drain it will only drop by about 200 litres across the two tanks - not very much.

UPDATE.. Went and bought my media today. 4 bags or red scoria. Only cost me $28.00 all washed now and ready to go. Some plumbing left to do and Im away. will post pics at the next stage

Hm... where did you get the scoria Rod? I reckon it would be lighter than my gravel and if you filled 2 x GB's for $28 I could afford it as well in the GH system.

Hi Mark. Out at Asq in Eaglehawk. I went for it because one it is lighter, two it is not bad to look at and thirdly it is cheap and inert. I went for the larger 14 mm so as not to block the siphon. The 4 bags though didn't cover two grow beds, it scarcely covered one. But that's the only way I could buy it and get it home. Definitely cheaper to get a trailer load. One meter only $60. If you plan on getting it by trailer we could split the costs and grab more

A

When you say 'scarcely covered one' how many do you reckon it would take to give something more than about 150mm in an IBC GB?