Backyard Aquaponics
A place to discuss aquaponics

Sounds good, polystyrene is an outstanding insulator

and will not degrade unless exposed to direct sunlight...

I need an update on your system's temperature steve No not really Just thought this might be the place to put this question - cause I know you are looking at various methods in your system. If the discussion takes off, can start a new thread.

My question is this. EB talks about a 2:1 grow bed to fish tank ratio. This is if you want to have maximum fish stocking rate in your tank (not recommended for beginners). Now is the 2:1 needed to house sufficient bacteria, or is it more related to the pulling out of nitrites (or nitrates, I never get it right) from the water after conversion by the bacteria.

Reason I ask is I want to know whether if I had gravel grow beds but also had an aeroponics bed (with fogger) and/or say NFT (is that the one with guttering), would the aeroponics and NFT contribute in any way to the grow bed side of the ratio and therefore help in building up fish stocking rate? Or would I still have to have the full 2 (of the 2:1 ratio) in growbeds.

Surely your other systems would aid in the removal of nutrients etc, but I would wager a guess that the growbed are NB for the bacterial action... so include a bio-filter for that, which allows for the breakdown of the amonia etc,and your other systems absorb the nutrients etc... Just not sure about the larger particles as a bio filter does need a clean from time to time..
HMMM

I'm not proposing to do away with the gravel grow-beds. I will still have these. It is just unlikely I will have enough grow-beds to get the 2:1 ratio and therefore have maximum stocking. I want to know if the other systems will suplement the gravel grow-beds and allow for increased stocking to get closer to maximum stocking rate.

VB, I'm going to give you the answer that makes sense to me, I may be wrong, so hold out to hear from EB, the master of all things aquaponic

I think it is to do with pulling the NITRATES out of the water. It makes sense when EB wrote about not harvesting the entire bed at once. You would be surprised about the amount of work a "small" amount of bacterial substrate can perform. From what i have read and seen in practice under ideal temps, ph and importantly water distributing over the media i have i believe i could stock to the maximum kg density per water volume.

See but then my nitrates will begin accumulating without enough plants. I could however have "mini ponds" growing azolla and duckweed, a few DWC buckets plumbed in and i reckon the expanded clay ball bed would house sufficient bacteria to process the ammonia and nitrites.

Don't forget is it S&S aqua that have the huge poly tunnels with a floating raft of lettuce? There is no grow bed there at all. They DO have a biological filter, but i'm fairly sure its not twice the volume of their pond, and i mean "POND".

All in all its better to have a ballanced system, as there is less to go wrong and less to leave to people like me to play with Using EB's tried and true ratios WORK, and you don't have to have a indepth knowledge of chemistry and biology to make it work.

Having said that If you can get your head around how each part of the system works and interacts, then there should be no reason that you could not play with "figures" and still have it work. For example, in my case i currnetly have 1000Lt volume of tank, 60Lt volume of grow bed, 5 small gold fish and now 5 jade perch in there. I believe these figures will work fine until the jades grow substantially. If you're going to play GOD with the figures (as i like to do ) then you MUST be testing the water. As my fish grow and/or i add more, i will monitor nitrates and can make a call on when i HAVE to add another grow bed.

The only other problem i see with having a very small grow bed ratio is that when you harvest its going to be hard not to take a substantial amount of your plants.

Hope this helps

Steve

PS, i have updates on temps, but will post seperatly, this one is long enough.

Damn, i write such long posts that two people get in with new posts even bofore i'm done

VB the short answer to your last post: YES (IMO)

Thanks Steve. I think you are right regarding just monitoring the levels when trying something different. One of the advantages of having these different parts to the setup would be the ability to harvest significant portions of grow bed plants, but have (for example) lettuce in tubes taking the nitrates out of the water while restocking the beds.

Hi all

Update on my temps.

I notice that the temp had dropped back down to the 18C mark after peaking at 20C.

A quick check of the heaters found one that had cracked and was full of water........how i didn't electrocute myself with my hand in the water would take too much brain power away from thinking about aquaponics

anyway, re adjusted the remaining two heaters (this is what i get for buying $10 heaters) and all is fine at about 18.7C

I decided to transfer 5 fo my jade perch to the outside tank to make friends with the gold fish (of which i have not seen since i put them in (its always dark by the time i get home ) I'm going to have a good look and play on saturday.

I probably couldn't have picked a worse time for the transfer as i just went out now, and the ambient reading i got at ground level was -0.3C a check of the weather webpage for the area gives me 4.5C.

The temp is still in the high 18's though, so the jades will be fine.

I aslo got my duckweed and azolla today

i div'ed it up between the aquarium in the lounge room, a few buckets outside, and a couple of containers in the kitchen, all of which i put water from my inside jade tanks. I also chucked some duckweed in the spa bath that i have stashed in the backyard for future fish tank, its just got a few inches of stagnant smelly water in it.

I'm hoping that i don't kill ALL of it I put enoguh in to each container to cover half the surface, so i'd like to check them again on saturday and hopefully see some growth. I might put a few pieces of dried chook poo in the tubs outside to raise the N content.

I aslo put a sizeable quantity in the aquaponics system that i just transferred the 5 jades to. the amount left by saturday morning should tell me if they are eating

Thats about it unless anyone has any questions

Steve

I've run the gauntlet with my old system a bit steve. My ratios are a lot different to many industry ratios I've seen and they were in the habit of removing solids.

Tips/tricks for running your system rich. (not for beginners please unless you have a firm grasp of aqua principles already as Steve does!)

Perpetual harvest. You need to plant in succession and harvest in succession. NEVER harvest everything at once. Partial water changes on harvest and afterward till new plants are rooting in the gap left.

Watch where your water returns. If it bubbles a bit (1-3ish inches) there's plenty of plant food. If the bubbles cover more than a few inches from your outlet you are beginning to get too rich.

Smell test. Takes no time at all. Always smell test your Aqua you'll know if somethings up pretty fast. I could walk into the basement and know immediately if there was a problem by checking my bubbles and if they were lots i'd blow some air in. Aqua is clean, (like decaying leaves almost, and a bit of worm poos) if you blow bubbles down a venturi linethat's the general smell. know your Aqua smells! If it evin begins to smell awful you are getting a bit toxic and should address it.

NO Anaerobic pockets. NONE! Ignore that it eats nitrogen. Do Not Get Too Clever You'll Pay!

Standby sponge or other inline filter for emergency nutrient dilution.

Fish feed more in warmth and less in cold. Bacteria work less in cold. This is a self regulating aqua feature. Do'nt try forcing more feed by having more small meals or less larger ones. If you must get the feed (for the plants) up in winter....

Supplement using organic foliar spray.

Good easy micronutrient sources - Worm castings tea. Parsley, silverbeet, spinach, in fishes water and/or diet.

A self regulating system is far more rewarding than building one up using risky parameters.

But it may take some of the fun out of it. And you'll never get the kill record behaving yourself.

My kills = 1 snail I crushed with a rock. 1 goldy died (euthanised) after 3rd bout of illness (flexibacter, this was my 'canary' fish). 2 small catfish (hole in head, pictus catfish = bad choice!), 3 algae eaters overwhelmed in the great bloom of 2004.

So, actual screw-up deaths. 3 algae eaters.

Nice tips and info there AA and Steve....

And VB, you're right, having the different methods all aids in the removal of nitrates and other nutrients from the system. Bacteria grows anywhere that there is a surface for it to grow on, it will be growing in an aeroponics tub, on the inside of your pipes and on the inside of NFT guttering. Fish don't like high levels of ammonium, but they can take higher levels of nitrates. So, as long as bacteria is present throughout your system, the ammonium nitrates are not all removed in a single pass through the grow beds, but more is converted into nitrates and these may be absorbed the next time they are pumped through the grow beds.... I don't know if I'm making a lot of sense trying to explain this.... To early in the morning and I've only had one coffee..

Thanks AA, very informative

Interesting about the bubbles foam, as i have recently noticed ALOT pof this in my indoor "staging" tanks. I have not previously measured nitrates, as the ammonia / nitrite readings indicated that the tank had not cycled, but after reading that comment i'll check tonight, and won't be surprised to find decent nitrate levels

EB, i'm sneaking a vistit home to check on posts......this is bad ......if i gte sacked i'll have to make aquaponics my life/job........Hmmmmmmm....

When I finally tested nitrate after 2 1/2 years being told to do so it was up to 160 ppm.

Everyone goes YIKES!

I put another bucket of hydroton in hooked up to recieve a trickle of water to add bio-filter and started watering 1% of system water to herbs in my garden that subsequently flourished in very little light.

As I was only topping water at that stage it increased my total weekly water changes to 1%.

And over two months brought my nitrate down to 120.

I don't know much about plant parameters etc. Nor hydro. But I thought I could stop being lazy about trying to collect some good data when I finish the greenhouse project.

Get standard industry feed ratios etc and see what levels the Aqua is producing at what stage of development, plus variances where and when they occur in order hopefully to understand why. Temps, season, new plants, fish, any input recorded. Minutes a day. Thought I'd put the record book by my fish and have a wee seat so I can chill and enjoy the whole process.

How the hell do you weigh fish without pissing them off?

When I want to weigh fish, to get an idea of how much weight they are putting on, I net about half a dozen fish one or two at a time, stick them into a clean bucket either individually or in pairs, sit the bucket on some scales and wait for them to stop flicking around so that I can get their weight.. Some people may say that only half a dozen fish isn't enough to get a real idea of the average weight of the fish when there may be a hundred or more in the tank, but, I don't want to stress them too much by trying to get more out.

Also you can tell if your getting out an average size fish or large or small one just by comparing them. If I pull out what looks to be an exceptionally small one, I won't include his weight unless I also pull out a very large one to balance it. Otherwise I just try to weigh average size fish.

AA, i have not got firm data for nitrates, but my tropical aquarium sits between 120 and 160PPM. Most aquarist would turn their nose up at this (me thinks people are falling for regurgitated info on the net too much ) But i have outstanding plant growth and the fish are happy and the angels breed regularly. You do realise that an extra hydrotron bed will only help with nitrates if there are plants planted in there (i'm sure you do )

I'll be aiming at around the 100PPM mark MINIMUM. Duckweed (from what i've read) grows best at 3% nitrogen which would be more than 30,000PPM. So the way i figure have the nitrates as high as the fish can handle. I'm inferring alot here, but if my angels still breed at 160PPM then i'd say they are still happy, and given that perch are MUCH more tolerant of bad water conditions that ornamental aquarium fish i come to the conclusion that 160PPM is good I'd probably go higher, but my test kits maximum is 160PPM