Backyard Aquaponics
A place to discuss aquaponics

[font=Comic Sans MS]Hi, Fellow Aquaponiacs,

In the days since my wife saw Joel’s piece on Gardening Aust and informed me I was about to become interested in aquaponics, I have come up with a few relevant thoughts. These have been prompted by the realization that I probably can’t dump some fish in some water and expect them to spontaneously grow to edible size within my lifetime. I am compiling a list of questions which most novice aquaponical fish- and veggie farmers will possibly want to ask themselves or someone else who knows, and I’m doing it for a purely selfish reason – I want to know stuff. So, here we go -----
1. Which is better, tap water or stored rain water ?
2. Is there a correlation between pond surface area and weight/mass/length of fish as there is with goldfish (I am told 27 sq. inches of surface area of pond per 1 inch of fish – you can work that into metric equivalents, and so can I, but not right now)?
3. Am I safer growing goldfish (pretty little carp) for a start or should I try for something edible right off? Goldfish are tough little fish, right?
4 . Would Euro Carp fed a non-mud diet be acceptable food, and if so, would they be easier to grow than other fish like Redfin or Callope or Silver Perch?
5. I feel it would be easier to stabilize temperatures in deep water than shallow tubs – 1.2m or 1.5m would be better than 0.6m – does this sound right?
6. How important is pH, and is the maintenance of proper pH just an extension of what my kid did to treat the water for his goldfish? What is the optimum pH for fish rearing, and does it differ for various species of fish?
7. Rearing is one thing, breeding is probably a whole new kettle of fish, so to speak - I know Cod are picky about water temp. for breeding, and that a degree of temp. can decide the sex of frogs, so are there fish out there who don’t really care and will breed anywhere? quite friendly :lol: that’s what I need, probably wouldn’t taste very nice, though!
8. Garden beds – what sort of gravel – do different gravels have different pHs or bacterial accumulation rates etc., -- what’s important here? I guess I can get back to the hydroponics people on this one.
9. I have seen Monya’s really impressive pump display, and feel it may be a little over the top right now, but the use of a diverter for aeration looks like a real good idea. I would hope to get away with a little less pump power and have a small assortment of fountain pumps, drill pumps(8 l / min) and such in the scrounge box. For the initial experiment I would suggest that a siphon tube and bucket might fulfill the needs. (Gravity costs not much)
10. Is the water from the ponds more suitable to leaf veggies or fruiting veggies ie. Lettuce or tomatoes?

Many more questions to come – I didn’t realize how many until I started on the basic questionnaire.
So far I have a 75 l fishtank and a bathtub, plus a vision of pans full of golden-fried fish – am I on the right track?
Big Mick
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Quoyr :- Give a man a fish, feed him for a day. Teach him how to fish, never get the lawn mowed. Big Mick

Quote:- Give a man a fish, feed him for a day. Teach him how to fish, never get the lawn mowed. Big Mick

So that's where spelling mistakes go ----- right up front.

Big mick, if you're on in about an hour and a half i'll have lots of answers for ya to ponder over a beer. You sound like a beer guy LOL

You mention redfin Mick, do you know of anyone who sells these as fingerlings here?

You have a lot of valid questions, and there are people way more qualified than me to answer them here, but here is what I have learned so far:

1 Rainwater is better
2 Dunno, but the more surface area, the more fish you can have (providing all other parameters are correct) due to better oxygenation
3 Heaps of people seem to use goldies to initialise a system. They grow fast in good conditions, sell em back to the pet shop when they get big
4 I reckon IMHO they would taste fine. I have eaten plenty of them when I was a kid out of the torrens
5 The more water mass the easier to keep everything stable including temp
6 Ph is really important, and it's really important what you use to raise/ lower it cause we are gonna eat the fishies. Aquaponics aims for 6.5-7.5, fish vary I think
7 LMAO at the quite friendly :lol: fish call. None of use that I am aware has had any success or even tried to breed
8 Lighter the better I suppose, something with plenty of surface area for bacteria growth, 7 or so mm
9 I got given the pump, and it has turned out way bigger than i need, but will use the folks ideas here to use it to my advantage ie airation, pumping to dirt gardens for water changes etc. I reckon go with what you've got
10 As far as I am aware, green leafies by their very nature love the stuff, but all vegies and stuff that you like to eat would be worth trying.

BigMick, take these responses with a pinch of salt. Anyone please correct me, I am only reciting what I hope I have absorbed from all my time on this forum.

When I joined there was about 1000 posts. Now look at the number. You have a lot of reading to do!!

Monya

When I read the quite friendly :lol: comment I got the best laugh I have had in ages. Tears streaming out my eyes

Yeah, that just came out of the blue, you're reading away, all innocent like and then BAM, cracked up

Steve, tonight I am a white wine guy, but it's not payday yet. Then I'm a beer guy. Mostly, I brew my own, but temperature is against me right now , plus my son just had his 21st and they drank it all. If I miss your reply tonight I'll get it at sunrise.Thanks in advance Monya, good stuff. Thanx for your time, we have similar temp zones, same water, so I will be looking out for your comments. VB,happy to contribute to your humour.

Monya, I don't know if or where redfin fingerlings are available, I just used to catch heaps of them in my little **umnet and I really liked eating them. I've caught a few recently in the Murray and thought that, like budgies, if you put a pair together you may get eggs, and then you may get fish.It's probably not that easy, but I have to explore these possibilities because it takes about 9 budgies to make a decent sandwich. and my wife is starting to notice the shortage. They are good roasted with Thai Chili sauce, if you were wondering!

Gee Mick , I thought there were only carp left in our dear delapidated river. My BIL said something the other day about a friend of his who bred redfin in a pond... Stay tuned will try and gleen more info.

Firstly, its good to see another South Aussie....

Well being currently fairly inexperienced in aquaponics, i can't anser many of your questions

But i do know abit about redfin (and yes they are still in our water ways...one good spot i know to catch them is in the torrens gorge, and if your lucky you will get the occasional trout too) Anyways back to redfin, redfin are an introduced species and are prolific breeders. Left unchecked they reproduce too rapidly resulting in whole waterways with only little runts (they overpopulate in other words). Im not sure about their growth, etc..... But i do know this, due to being an introduced species and being prolific breeders they have claimed themselves a "pest status" and legally you are not allowed to return them alive to water......... (not sure where this pest status extends to, as im pretty sure interstate they are prized and protected)

However i do know two people who have redfin, one is an aquarist...and the other an angler (both who also live in Adelaide)

Oh, another thing about redfin, they taste good!

Oh and i will be checking this post regulary to gleam answers from your questions

Big Mick,

Monya has done a good job with those questions, i'll add some comments later, but nothing he said is wrong in my opinion.

ErisKSC has just posted under FISH-->HI ALL about native rainbow fish.

Sounds like these are the quite friendly :lol: fish you are looking for, he reckons they spawn morning and night 24/7 gotta keep this relativly clean, aquaponics is shaping up to be a school project sort of thing

Unreal, i mentioned the beer thing because you bear a striking resemblence to a great bloke i used to work with, laughed when you mentioned the home brew, he was into it too, and i remember one summer arvo he ran out of work at knock off time like a bat outta hell for fear that the yeast in the brew would die due to the temps!

didn't have any rellos in melbourne did ya? LOL

Mick, i'll just add some comments to Monyas answers


2 In aquaponics you have a fair amount of oxygenation via the return water if constructed properly. The limiting factor IMO becomes the ability of the plants to strip the nutrients out of the water, not the airation which is what your quoted surface area takes into account

3 Silver perch are also very hardy, and actually cheaper than goldies if bought in bulk. Trick to cycling is to try and add fish gradually, not feed too much and make periodical water changes in the first 4 to 6 weeks. Having said that i used goldies as they were easily obtainable in small numbers

5 100% correct, also helps in not killing fish when initially cycling the system. Ammonia waste from fish is measured in Parts ammonia Per Million parts of water so larger water volume will help out here, esp. in the first 4 to 6 weeks.

6 Good choice of PH range, i'd not personally operate outside monyas stated range. A properly cycled and functioning system will drift down in PH naturally. My choice of buffering for the system is to incorporate sea shells. This will stop it from going below 7.0 and adds calcium plus a few trace minerals


8 highly porus / irregular shaped media works best IMO, But whatever you can get your hands on that suits your setup

9 Damned excise tax on gravity.......LOL.

10 Traditionally all the info you could find on aquaponics stated that it only suited the green leavy veggies like lettuce. Joel and others have proven beyond a doubt this is incorrect. Browse the album and see the tommies and peppers

Mick, if you haven't ordered a copy of joels book i'd reccomend it. It covers all the tried and true volume versus stocking densities and much more.

Personally i'd use the bath tub for the fish, more water volume.

Read some of the info in the "useful info" section if you have not kept aquariums or are a little sketchy on the nitrogen cycle and water parameters.

Hope this has helped.

Steve

1. Rainwater may/may not be better. It is entirely debateable depending on your source water. Mine is fine and I'd not switch to rainwater as I'll then be adding all the sprays exhaust fumes and other city crap that accumulates on my roof in dry periods.

Key points in this debate - what is your source water like, where is your system and collection tanks located in relation to urban development and industrial areas, do you have chlorine or chloramine.

There's a reason humans aren't allowed to drink rainwater in Auckland, and it doesn't fit the clean green NZ image they try to push.