Backyard Aquaponics
A place to discuss aquaponics

G'day from Browns Plains!
I just stumbled onto this forum two days ago and It's fantastic!

You guys seems to be right at the leading edge (bleeding edge?) of Aquaponics and I think its great the way you brainstorm & experiment to get good solutions - and share the knowledge!
I have read many many pages - and I'm sure there are gems of info everywhere here - unfortunately there are not enough hours in the day to read the lot. So I have a few newbie questions that people have probably asked a million times - please be kind to me

I plan to retire in 4 years and want to be self sufficient (I'll be poor but happy). I discovered Aquaponics a couple of months ago but I have little experience in keeping fish.
I think I have already made my first mistake. I went out and bought a 10,000 litre circular above-ground pool (food-grade liner). My idea was to buy 100 silver perch fingerlings (highest Omega 3!). I figured that would be a fairly small number for 10,000 litres to start (?). I figured if they grew ok that would be 100kg of fresh fish a year!

I have filled the pool with rainwater & its got a few guppies in it to eat the mosquito wrigglers.
I was planning to build a biological filter from this website:
Skippys

but the idea of using the plant substrate (gravel) as the filter is far more appealing.
So these are my first questions

Problem is I am beginning to understand I will need a massive number of grow beds to provide adequate filtering for 10,000 litres. Is the ratio 1:1
ie 10,000 litres of gravel for 10,000 litres water?

I phoned up an aquarium shop and he told me I would need a pump capable of 10,000 litres/hr to treat the water. In my ignorance that sounds like a lot - turning over the entire pool every hour.
In your experience what capacity pump would I need using grow beds with gravel?

About continuous flow systems: How does the water and the plant roots get adequately aerated? I followed the thread about auto-syphons (brilliant) and the flood/drain method seems a better system. What are the pros-and cons?

That's all my immediate questions - just waiting for Joels book/cd to arrive!

I would appreciate any advice on my next purchases.

I will need the pump. I really want a solar setup but that will come later.
I think I want the comfort of an aerator (got questions about the best type - efficiency/cost & power).

The hard bit is the grow beds. I don't have the time, energy, space or cash to erect 10,000 litres of beds - 10 cubic metres of gravel!
Got any suggestions on how I can get away with a smaller area of beds - maybe 3 X 3 x .3 (2.7 cubic metres)?

For fish food I was planning to use chook laying pellets + stale bread mixed with eggs (got lots of eggs). Today I read about duckweed - sounds good. Any thoughts on this diet?

Thanks in advance


Regards
Jamie

Hey Jamie.

Firstly, max stocking densities of 6 kg of fish per 100 litres of water can be achieved if you have twice the grow bed volume to tank volume. ie if you wanted a 10000 ltyr tank, then 20000 litres of growbeds would support 600kg's of fish But there is nothing to say that if you had 10000 litres of fish tank and say 5000 litres of grow beds, that you couldn't stock at 1.5 kg's per 100 litres ie 150 kg'd of finished fish. You have to work out the kg's of fish at eating point ie if you get 100 perch, it's most likely around 50 kg's as you would probably start eating them at 500 grams. BTW, Jade perch are actually the highest for omega 3!

Obviously, the more times you turn the water over the cleaner it will be, but I don't think once per hour is neccessary. My system pumps out 800ltres to 2 grow beds, and they take an hour to drain, so that means turn over of once every 4 hours I'm hoping this will be sufficient.

The problem with continuous flow is getting all the gravel wet hence keeping the bacteria alive. Continuos flow can tend to render a lot of the medium useless, wheras in flood and drain, the whole lot gets wet. As the water drains through, it drags air down, hence oxygenating the water and the plant roots etc.

Have a good read of the book. Most of us have it I reckon, and it's excellent. My system is modelled directly off Joels, with a few added extras for fun and experimenting.

Good luck with it!

MOnya

Monya, ya beat me to the jade perch

Jamie, with a system that size, think out your setup carefully, as any errors are probably going to cost you $$ .

Monya is correct, Ultimate grow bed volume will be governed by the max amount of Kgs of fish you want to hold.

Another way to look at the "formula" would be 200Lt of growbeds per 6 Kg of fish.

Steve

Browns Plains in Brisbane?

Hi Jamie, is that Browns Plains Qld, if so you might like to read this:
http://www.backyardaquaponics.com/forum ... highlight=

A meeting is going to be held in your area at the end of the month and there will be a number of people attending that will do a "1 on 1" with you also a running system will be on show

Re chook pellets - this has been brought up but was discarded, read this:
http://www.backyardaquaponics.com/forum ... .php?t=190

I think that just about covers your initial q's

Ell

Sorry Monya, but where have you actually seen these stocking rates?

2:1 Stock up to 4 kilos will stop you killing everything. 3 kilos for a new person is PLENTY!

You can have 1 kilo of fish in there mate. Or 10 or 100. 600, you'll lose em all unless you are an expert already.

1 kilo fish will require 0.6 canopy cover of leafy veg. Or 0.5 of more substantial plants.

It's all to do with your stock. If space is the limiting factor use above stock rates till you can't fit anymore beds.

Joels book is worth every cent.

Enjoy.

AA, Joel's book quotes these as MAX figures for a nice balanced system.

Thanks for all the feedback
I guess my concern with having too big a tank for the number of grow beds was that:
1) If I have too small a fish stock, the concentration of nutrients would be too low?
2) If I increased the fish stock (to get a higher concentration) - the biological filter (the gravel) wouldn't be adequate to cleanup the water?

So I guess its a case of suck it and see
Maybe turn over the water at a lower rate so the nutrient concentration builds up (keeping an eye on the ammonia levels). This is going to be more of an Art than a science.
btw - how do you control the flow of a pump - just play around with the head? Thought of getting a Laguna max flow 6000 - sound reasonable?
I like the 3 year warranty & low power.

Thanks for the info about Jades and Omega 3 - It'll be 100 Jades now.

El - I couldn't find any reference to Chook pellets being no good (maybe I missed it).

Donarto - yes - Browns Plains, Brissy.

Cheers
Jamie

Hi Jamie, so you plan on having 100 fishies? Your should be able to start there with little problems and add grow beds as you increase stocking density. Sounds like you will have plenty of room for the fishies.

Ah, OK Monya, I have read the book twice doh.

I don't know if Joel or S&S system growers have actually gone to that stocking rate but it would certainly be possible.

It is a LOT. Especially to recommend to "Absolute Newbie questions"...

But there it is, it'll work. If you're good imo.

The highest I've stocked, where the fish seemed (looked, my old softy perspective?) comfortable, would have been 3 kilos to 100 litres.

But that's me. I get attached to these fish, I'm not eating these fish (some of the kokopu perhaps we'll see what size they hit) so it's a part aquarist part aquaponist point of view I guess.

It was also a point of issue on your organic certification process, the ability to stock this high...

Sorry to sidetrack so much in your thread Jamie.

Apparently - ou can have HEAPS of fish

Oh yes Jamie. I have 1 kilo fish in 600 litres water growing a 50 litre Aqua bed at the moment. If the water goes through the bed the bed will grow. say 1 turnover of the tank every two hours, the plants get to feed on whatever goes by from the water 12 times a day....

So you can just make it as you go, and add fish and plants. Check Steve's instructions on the home page, chuck a few fish in, find a container and start cycling it. Then plan at leisure it'll already be started.

Obviously I have room for more fish, and now, some bacteria in my bed and fish water making plant life explode, seed bacteria for the larger system I'm making around the pond.

Thanks Guys
More stupid questions:
1) Is the output from a pump linear in relation to the head? ie Max at 0 head, zero at Max Head and a straight line in between?
2) Seems to me the *critical* things to watch are the ammonia and the oxygen levels (remember I know nothing). What sort of price is equipment to check these? I get the impression the oxygen equipment is expensive. Would this be a robust kind of machine that maybe several people (in Brissy) could buy and share use of. Or is that not practical.

Cheers
Jamie

Welcome to the Forum Jamie. I read your posts and a couple things stood out.







This is absolutely true. The point of aquaponics is to balance fish density with bio demand of plants. I think 10,000 liters is too big to start unless you have time, space, and resources to expand the node as you stock the tank . Not to say you shouldn't do it, but keep in mind that initially you will not be able to utilize this volume to it's potential until you have growbeds, and therefore will cycle very very slowly to allow effluent to build up, maybe for several days at a stretch before you even water the growbed/s. Ammonia won't even register in a tank this size unless you stocked it with 500 fingerlings. Whatever you grow intitially in the growbeds will not receive enough nutrients, so don't expect lush vegetation off the bat.

Jamie, Welcome! I'm technically Newbie too (although I post alot I don't really know anything!) I think it is Jade perch that are the highest omega 3 not silvers (see ausyfish site) Very cool more queenslanders! Enjoy this is a great forum!

EDIT: ergh. I didn't see that others had mentioned the jade perch already. sorry. (damn, that was one thing I actually knew! )

Jamie, hope we're not all confusing the hell outta ya!



True if you mean fish to plant ratio, but NOT true if you mean fish to water ratio.

Just wait until nutes have built up a little before planting out and then balance the plants to the amount of fish and nutes will stay static.

Agree MF?