Backyard Aquaponics
A place to discuss aquaponics

Veebs, sounds like a test. i WILL do it as soon as i have my BYAP system running with trout.

I personally believe that there would be negligible NH3 or NO2 from switching the beds off.

look at it this way. 1ppm in 1000L = 1000mg = 1g NH3

SO your fish would have to produce ONE GRAM of ammonia over 12 hrs to show 1ppm in the morning (for a 1000L tank system). This is not taking into account the biofiltration (slight but still present) being done by the bacteria on the inside of your tank walls.

DanD reckons 100 x 400gm Tilapia will produce 0.1gm of ammonia / day ...

viewtopic.php?p=121979#p121979

I wonder if diet would increase that at all...

i.e feeding high protein pellets to Perch, Barra etc....

Would they poo more and/or would uneaten pellet feed produce more ammonia/fish/day compared to Tilapia on a vege diet???

doesn't really matter ruper. even if you double those figures that you're still only going to show .2ppm if you had 40KG of fish in 1000L with the beds off line for 12 hrs.

know what i mean.

Hiya Rupe,



Well we're talking about not cycling water through the GBs at night in cold weather ... SP aren't likely to be feeding much in cold weather anyway.

Knocking up a fluidised sand filter would be the go -DanD has written a lot on the subject

My SP were eating quite well at under 12°C, but since temps have spent the last few weeks around that temp, they have all but stopped eating.
Last winter they waited til the temps were up around 15-16 regularly before they came back on the bite.

Pretty sure the lowest temps I saw last winter were around 8°C? Fish were active the whole time, just not interested in food.

A bit of a hijack, but on my gold fish flakes package it says "Do not feed if less than 10 degrees".

I assume this is an arse covering move so people don't overfeed their fish. However, what if it's because the fish don't digest at below 10? I am feeding twice a day and they're looking bloated....

I guess it's a general all fish question really: Does temperature effect their digestion in addition to their appetitie? Will they still eat but then explode? Or have they evolved properly and hence don't eat if they're still digesting?

If you are running your fish considerably under their preferred temperatures you are .....,
1) Stressing them
2)Stressing the good bacteria because almost zero food input
3) Wasting good grow time
4)Probably causing slower growth later ..... example , Tilapia growth slows considerably after they are 6-7 months old ,, slows considewrably if they happen to be 100 grams or 700 grams.

The world is FULL of cheap / good insulation and Australia has cheap electricity ,, why not heat?

I'll do a theoretical cost benefit calculation tonight ,,I recon money is being wasted by not heating.

because most of the heat is lost via the growbeds, not via the sides of the tank...................

to maintain SP feeding well id say you'd have to heat to say at lest 16C preferably 18C.

My suburb in Melbourne reached a grand total of 14.2C today for a whole 20 minutes.................

So, unless you're going to heat to 14C and pump water to your beds for a grand total of 20 minutes in 24 hrs, then there is a problem. Not including the one that although the air temp got to 14C for 20 minutes i'd suggest that the growbed internal temp never got above about 10C...............................

Anyway, the last 3 SP i had died last night. repeated 8C getting them.

Once again, its the growbeds NOT the tanks lack of insulation that does the most damage.

I have my tank buried in the ground so its not losing heat below the ground temp which is about 15C i think............

For anyone that attended Dr lennard wilsons place they might have noticed that the tanks were in an insulated and heated shed, the plants were in a polly tunnel green house, and even the pipe work in between was insulated with the stuff used for boiler lines..................

Grow the fish you can for the climate you have.

1Kw is 1Kw regardless of how many cents it costs. Cheap energy is what got us into the mindset that the last 100 golden years is normal. Its not. it is a mere anomaly on the time line of human existence.

Echo

Steve for president

+1

Grow with nature, not against it.

I wrote a long detailed reply,.....,,f-ing internet self disconnected and I couldn't be bothered writing it again.
I choose to plan ahead for heating ALA Dr Wilson.

I wonder how many BYAP ers are reading this forum sitting in front of a 2000 Watt heater?
I don't need a heater nor airconditioner because I planned ahead( house design).
If I want to use some power to extend the usefullness and economic viability of my AP system what is wrong with that?

If we want to go back to the methods of a hundred years ago,may I ask who will be choosing the estimated 30-60% of people that will need to be ...removed/composted. Sure hope it's me.


Quote from Steve"Anyway, the last 3 SP i had died last night. repeated 8C getting them"

Quote from OBO "Steve for president

+1

Grow with nature, not against it.
'
The two quotes are in serious conflict.

That was what my comments were for.

I am not doing AP to have the most whizz bang everything running flat out system I can.

I am not sure what size SP steve has, but if they were small that would have been the problem. SP can survive low temps without getting stressed once they are bigger. Gnash and I currently have the same problem with SP. We got the fish at the wrong time of year, and some are not big enough to winter. Therefore we are not growing the right fish for our climate at the moment. As long as we grow Trout over winter, Barramundi or Tilapia over summer, and larger SP all round, our systems are very productive, run efficiently, and with minimum power inputs for maximum growth. I dont care that the SP are not growing hugely at the moment, I have awesome Trout doing it instead.

Sure we could heat our tanks, I would love to have my SP @ 28 deg c right now - please show me an efficient way to heat 5000l of water hooked up to a 3000 litre, 8 metre x 6 metre radiator - and everyone would do it.

I really really think that there is no need to heat a system for a whole winter. Obviously if you have a large source of free heat - then go for it. I sure as hell dont.

When it gets to summer are you going to be advocating running A/C chillers to keep trout?

I choose to plan ahead to not heat.

Not having a go, just stating the view that I have.

Colin

No worries OBO,, there's no problem agreeing to disagree.If we where all the same it'd be a bloody boring world.

I'll even throw in a sweetener ,, if my plan falls flat on it's face you can give me 20 dig in the rib posts free of charge:)
I'm not going to be an environmental terrorist and have limited power usage to 8 kwh per day through winter., as stated we don't use a home heater or air-con ,, we have been using power saver globes but I'm now thinking of installing whale oil lamps to save the world from coal burning power stations.



Let me fall on my ass and then I'm happy to be suitably RAZZED.