Backyard Aquaponics
A place to discuss aquaponics

Ozzie,

I understand the need for stability, particularly with fish involved ( I don't have fish , but worms that more closely match the temp needs of plants). And, with fish, I can see how more water might help with DO.

But I don't quite understand the necessary correlation between a larger water body and a more stable water temp. It would seem the opposite to me . . . that it would easier to control the temp of a smaller water body than a larger one.

I mention this because I am attempting to stabilize water temp buy using a smaller body of water. I think the solution to more stable temps is in the relationship (ratio) between the mass of water and area of exposure to higher or lower external mass temps. It's one of the reasons I'm switching from gravel beds to floating rafts.

m

Larger body of water will be more stable (not necessarily easy to control though, takes a lot of energy to change the temp of a large body of water.) Small amounts of water might be easier to heat or cool but they won't have the mass to maintain that temperature if the entire system is not well insulated to the desired temperature. Remembering that flood and drain gravel is pretty efficient at bringing the water temperature closer to the air temperature.

Converting a system to raft beds will likely help make the temperatures more stable because of the greater amount of water and if the flood and drain bed is in a well insulated space with a desirable air the temperature, the system temperature will likely swing less.

More water more mass MORE stable temps.
Put 1ml of water in a microwave on high for 30 secionds ,, now try 3 litres

Chappo,

It is true, given all other conditions being the same, it will take longer to change the temp of a larger body of water. Longer, but not impossible to do so. If exposure is high to temp differentials, it will happen anyway. Then, once temps have changed (presumably for the worse), it will take longer and more energy to bring them back to a desired range.

Seems to me a better, possibly a cheaper and more efficient, way to stabilize temps is not let them get out of hand in the first place. Minimize the exposure to temp differentials, and a larger water mass won't be necessary. Less water will likely be easier to control.

m

If you have a extremely well insulated greenhouse and are controling the external envirnmental temperature variations then yes the excess mass isn't needed for that. Water volume is in most AP'ers favor because all the water parimeters change more slowly and are easier to detect allowing more time to make changes with less harm to Fish and possibly as with ph your worms.

If you are talking "controlling / inputing " heating or cooling ,, then the answer is yes.

All good, BRB. Colony raising French Angoras when I have their food grown.... just housing them at night for protection. Into Permaculture now.... integrating it all. Don't want to buy in food for any of the animals... all hom-egrown. The AP, rabbits, chickens and Moringa foodforest all in zone 1..... easy access. Might bring the Jerseys this close too...with all that milking.... but the goats will be further out. My tilapia are still up top waiting... trying to get it right with waterproofing on a small pond in the foodforest... whew!... third try coming up.... now going to use coprox in the cement mix... not even going near my AP sump building till I can get this right. But the slab is laid. Like what Mornings has achieved with his vermiponics... want to integrate a bed of earthworms between the pond and GBs. Looking into best media to put them in. The GB media will be too rough I think. They could process the rough detritus before it clogs the GBs... Just something narrow as a pre-filter that empties as it fills I think.

What rabbits you getting? I have chosen FAs because both meat and wool..... dual purpose. Might just feed the rabbit dropping straight into the earthworm pre-filter too to feed up the worms more and further enrich the plants. Will have to learn what I can do and not do. Got to get this water-proofing properly figured though.

This temp thing can be quite something I think. The pebbles I will be using can get very hot in the sun.... I found that out when I sat on them in the middle of the day... I moved real quick! Great for winter to heat up the tilapia and frequent cycling could keep the GB within correct parameters for the plants I think. Going to be interesting. Summer I will have to use shade cloth... no doubt about it.

You would naturally be thinking in terms of vermiponics M. But with AP the larger body of water I am convinced would be best. It not only slows temperature changes.... best for fish to adjust .... but is conditioned with all the essential bacteria needed to function optimally in the nitrogen cycle..... like a bank with all the good stuff. Fresh water top-up water would not dilute it much. Fish are more trouble... agreed.... but I really love raising fish... so not effort for me.....Love eating them too. I saw a guy on TV once... eating an earthworm... just not for me and protein production is vital in a sustainable situation. I suppose you could dry and powder the earthworms... you thought of doing that? Earthworm flour... ... made into cookies. Best to feed the fish and eat the fish! I also want to go as low-tech as possible... less maintenance ..... fewer problems...I hope! .... and so not interested in careful monitoring of a smaller system and buying all the techno to keep it running optimally... and too busy for that. Problems must develop slowly enough for me to get to them in time. I have seen what failed heating will do to Oscars... not again. Want natural and low-tech as possible.

Remember that your pebbles may be heavily shaded by plants so might not give you as much solar heating as you would like unless you nitrates are way down in winter due to cooling and thus you remove plants in order to get some more sun on the pebbles in some of the sunnier grow beds for the winter.

Some shade cloth will be needed in summer but hopefully the plants will take care of much shading for you, it might depend on how much you open up the greenhouses for summer. I have not had my water temperature threaten to get too hot and I think our climate is a bit warmer than yours most of the year. I also expect you will have far more water than I do. I expect that water being too cool might be your biggest problem but if your tilapia are surviving outdoors over winter now then in a greenhouse might be able to counteract the chilling effect of the flood and drain gravel (might just mean not running the flood and drain during the coldest part of the night or something like that.)

Pebble colour will also have some influence.
White on top if want to keep it a bit cooler.

Wow, lots of work!!! I like the Permaculture thing a lot but haven't had time to work much in my side lot. I will be planting some potatoes in my compost boxes and Probably feed grains in my dirt garden for the chickens/quail in the backyard. I also purchased a pellet mill which I plan on making rabbit pellets out of my lawn clippings. Like you I want to be self suffecient on animal feeds including the fish feeds. I will keep the rabbits caged due to the constraints of suburban life. I found the tilapia like the chicken scratch grains and seem to be growing well with it and it doesn't stain the water like pond feeds. I plan on getting New Zealand White breeders in February and possibly some Flemish mutts.

Yes, I can see it is going to be a learning curve. I might just use black piping in a return circuit in winter such as you did TC. The new pond will be in shade in summer under an existing mulberry that is a favourite... enormous... so not willing to remove it. So water will be cooler in summer when going to the plants. In winter thankfully it is decidous and opens the pond to sunlight. I don't want to compromise the needs of the plants in my efforts to care optimally for the tilapia.

The plants will no doubt tell me fast enough what is needed. For the GH I am going to thread PVC piping with thin round steel rods and then stuff it with cement. Have tried this with something else and like the result. Cheap and strong enough for monkeys to jump on.... I think .... when dried at the desired curve. Plastic over the top and shade cloth attached as needed below..... just tied on in sections as needed. It is new plantings I am most concerned about.

That is good to hear. We get pretty hot here though. Late 30's in summer regularly... not sure what that is in F. That the pond will be shaded might be a real plus.

Only the GBs will be undercover ...... against monkey thievery. The pond will be alongside but outside. Thank goodness monkeys don't eat fish! And commorants are not likely to come to this site... can't see it from the sky... well in summer anyway. We have fish eagle too... but they need to swoop and grab in flight so not easy for them anyway. In winter I will stop all flood and drain overnight. The gravel I will be using is very convoluted in shape so should hold enough water to tide the plants over I would think. I think it was OBO who said he does this.

That is a neat idea. Yes. Good reflective light too.

What are you "compost boxes" that you are planting your potatoes in, BRB? Like a stacked tower with compost instead of soil? I also want to grow my own grains for feed.

How your quail doing? Read up on them cos of you doing it... fascinating little birds. Going to add them sometime too.

Neat idea about pelleting lawn clippings! How well would they keep?... through winter?

Keeping rabbits colony style does need space but can be done a little with an outside run on slab for ease of cleaning... I wouldn't keep them in the same place day on day on grass... coccidiosis built up needs to be prevented and a general swill down with chlorine I was told will keep things hygenic... probably bleach too.... I would prefer that cos cholorine has certain health problems attached to it. The caged animals definitely need a rest plate for sore hocks... they have no padding underneath their feet... and I have noticed that a lot of people forget or don't know this. Just a piece of wood in the cage will do it.

Interesting that the tilapia take chicken scratch..... they are such great little fish! So easy to keep.

NZW and Flemish are big rabbits... meat... very good size. You going to tan the hides? I have a tanning recipe if you're interested. Just on my laptop at the moment and is on my desktop... but ISP is down at the moment.

I have heard on a few forums that the NZW can be bad tempered. But occasionally some have said theirs aren't. Probably just need to eyeball the animal and see how it takes to handling before taking delivery. Rabbits don't naturally like handling in general but if handled from kits while still in the nest they are less stressed with handling... and some even happy to be handled. That is obviously the best. An aggressive NZW can make checking her litter a very unpleasant business. Someone I know breeds French Angoras and intorduced NZW into her one line to improve conformation in terms of dual purpose... more meat and rounder shape.... she shows her animals regularly and wins frequently... but said the NZW introduced bad temperament along with the good physical characteristics she was seeking... now having to breed them back for temperament.