Ryan's system

ryangus

Now that I'm suitably convinced of the merits of AP, I'm keen to start my system. I'll create a small system first, to gain experience and keep costs down, then hopefully move on a "family size" system in due course.

To save not having to run power and water to the back half of my back yard, I'm considering starting closer to the house, with the FT located under my back deck. This will use up currently wasted space, and make powering the pump much easier. I do have some reservations, however...

Below is a sketch of my draft plan:

Some of the concerns/questions I have are:

Will the GBs get enough sunlight?
I was planning on a flood/drain system. If I make the return from the GBs higher than the tank, they will sit too high for my liking (I'm not very tall). If the return from the GBs aren't higher than the FT, how can they drain? Would this mean I would need to have a sump (and pump, which I'm trying to avoid)?
How do I make the pump from the FT to the GBs switch off at the precise moment. I fear an electronic timer would be to imprecise. Would this mean using a float switch, and if so, suggestions would be appreciated.
If rain water enters the system, would an overflow in the FT take care of the additional water?

Thoughts/suggestions/constructive criticism gladly accepted.

Regards,
Ryan

jessy

Greetings Ryan. looks like your on your way :cyclopsani:

Outbackozzie

One pump in the sump, that runs on a float switch. It pumps from the sump up to the fishtank, which overflows into the growbeds. The beds drain back into the sump.

Advantages - Pump is in clean water, so less maintenance.
You cant accidentally pump the fish tank dry, which is a very good thing.

ryangus

jessy wrote:

Greetings Ryan. looks like your on your way :cyclopsani:

Thanks

Outbackozzie wrote:

One pump in the sump, that runs on a float switch. It pumps from the sump up to the fishtank, which overflows into the growbeds. The beds drain back into the sump.

Advantages - Pump is in clean water, so less maintenance.
You cant accidentally pump the fish tank dry, which is a very good thing.

Of course! Can't believe I overlooked that, or didn't see it in the hours of research I've done!

So, for a 500L FT (which I assume will only actually have 400-450L of water), how big should the sump tank be? Would the FT need the overflow inserted in the side of the tank. If so, I'll need to ask the manufacturer to include it - what size shoud it be?

Also, any recommendations on pumps?

Thanks for your advice

Outbackozzie

a 500 litre fish tank will only require 4 x 1/2 blue barrels at the most, so the sump should be at least 160 litres. This accounts for all the blue barrels being full at once (40% water)

ryangus

Outbackozzie wrote:

a 500 litre fish tank will only require 4 x 1/2 blue barrels at the most, so the sump should be at least 160 litres. This accounts for all the blue barrels being full at once (40% water)

Hmmm... must have got my ratios mixed up. I thought a 500L tank would support more than 4 half barrels. At least that cuts down my costs a bit

So, for the sump tank setup, the overflow from the FT would need to be higher than the GBs, and the GBs higher than the sump (or am I missing some fundamental principle)?

Snakes

I also thought the ratio was 2:1? If he's got 400L it should support 8 half barrels (800L)?

ryangus

Snakes wrote:

I also thought the ratio was 2:1? If he's got 400L it should support 8 half barrels (800L)?

That's what I thought, too!

fishfodder

2:1 is generally seen as the maximum for a backyard system, however 1:1 is more the norm as it means the system is far more forgiving and less fishies get killed.

Also if you look at 8 half barrels filled with 40% water then you have 320 litres out of your possible 400 sitting in gravel, doesn't leave much for the fish. This is why lots of people employ a sump and use a SHIFT PIST system, lots of info on this elsewhere so I won't repeat the info.

Great plan to put the tank under a deck as long as you can get the fish out easily.

:cheers:

ryangus

4 tanks should be fine - I'll probably end up using this as my herb garden, with the FT becoming the nursery for the bigger future system.

I still am confused about the heights required for the FT, GB and sump, as mentioned earlier. Anyone care to enlighten me?

Outbackozzie

what FF said. It is quite hard to get a 2:1 Ratio without running something out of water at some stage.

Outbackozzie

heh

Fish tank is at the top of the system. Growbeds just below maximum water height (100 - 200 mm at least), sump below that.

Fish tank

..............growbeds

....................................Sump

monya

fishfodder wrote:

2:1 is generally seen as the maximum for a backyard system, however 1:1 is more the norm as it means the system is far more forgiving and less fishies get killed.
:

I would have to differ on that point. 2:1 means you have 2 times the growbed to tank volume, and therefore twice the filtration as if you are running 1:1. So 2:1 would lead to a more forgiving system. 2:1 means a big sump to hold the whole volume of the flood, but that is the only minor negative. The only reason 1:1 is more the norm is because most people don't have the space or resources to go hard and double the growbed volume and make a mega sump to hold the whole flood IMHO 2:1 should still be the goal, even though I have run my first system at 1:1 I wish it was 2:1 as I could have pumped a lot more food into the fish and hence watched them grow out quicker. Our new system is 2:1 with a big sump on chift pist and it is VERY stable.

OBO that is right unless your sump is sized correctly, in which case no part of the system would be likely to run out of water so long as you top up the sump as per any other style of system requiring topups..

Outbackozzie

Thats why its not really a water to growbed ratio, its a fish to growbed ratio.

4 x 100 litre growbeds will give you the capability for 40 odd 1/2kg fish.
500 litres of water gives you the capability for 50 odd fish.

Going bigger for the first system is probably not necessary, becuase it will only be a quarantine system once the bigger one is built.

If you put more fish in the same amount of water, even with more growbeds, it will not be more stable, because there is less room for error.

50 fish in 500 litres of water, 1 hour power failure - might be ok.
100 fish in 500 litres of water, 1 hour power failure = dead. 8 growbeds wont help you now.

Depends on what you plan on doing with this system down the track.

fishfodder

The confusion is just a matter of interpretation. If we are talking purely fish tank water capacity to grow bed capacity without employing a sump as per the original drawing then 2:1 doesn't work very well. Employ a big enough sump and all is well.

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Ryan's system

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Backyard Aquaponics A place to discuss aquaponics

Ryan's system

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Backyard Aquaponics
A place to discuss aquaponics