Backyard Aquaponics
A place to discuss aquaponics

Ok ,,here's a link ???

http://www.protherm.com.au

I have no affiliation with this company and plead the 5th amendment,,,LOL

The only reason I know how good this stuff is ..........
I live in an old house in a very nice suburb ,, decided to renovate . Identified major problems with house , one of them was that the small sunroom at the back got so hot that I ncouldn't be in there. Anyway , we started nour ecxtension ,, flat colour-bond roof and i was VERY worried about getting the same problem as our lounge/dining room was to be where that old sun-room was . i had previously used a local guy to BATT my house's roof , asked him areopund to quote on wall BATTS and floor BATTS. I took the opportunity to chat with him about the heat worries I had. He recommended this Aussie made Thermal "Protherm" , I envisaged a nice improvement and a reasonable temp in summer.
Dur to our builder's desired techniques the "Protherm" was not placed in the best position and to be honest i was worried ,, well shoot me down with a duck-feather ,, it worked like a DREAM. temps where the old sunroom was and the new dining is , where at least 7 degrees cooler ,, perhaps more ( in our summer heat of January ). I was shocked.
I starting to sound like and advertising campaign ,, but truly the difference was amazing.

I figured if it was so good at keeping heat out ,, if layered in the opposire direction to keep heat IN ,, it should give similiar excellent results ( thus my test tonight on the water bucket in the back-yard.)
I'm about to take the next set of bucket temperature readings.

Sounds like pretty good stuff. It looks basically like the bubble foil types stuff but better than the foil/mylar right?

Around here I would probably wind up using Tek Foil from grower's supply or something if I were to insulate a container myself any time soon. I kinda expect to find an old used water heater or something for the project if I get serious with it. If It doesn't happen for a long time and we get to the point of construction on the "new big" house, I might need to plan a concrete water tank insulated with polyurethane foam. (that stuff is really good insulation but it is $$ so I would only do that while the guys are on site spraying the house form.)

The water actually went in at 29 C , 3 hours ago. ( 4 beers ago) Air temp 10C.
Uninsulated container now at 20 ,, I was actually expecting lower.
Insulated container now 27 -( 27.5).
Assuming a linear decline , water should be 24 -24.5 in 6 hours time.
The test buckets are placed in open air ,, near to where the propose grow bed will be.
The fish tank , well " container" is to be about 3 cubic metres ,plus a primary bio-filter ( bio-balls approximately half a cubic meter) in a shed , fully insulated , same material I used on the bucket but better applied than a bit of sticky-tape.

Because we are theorising on the warm water system , lets assume a maximum demnd scenario at this time frame..
We need a starting point , so lets say we used that dmaned dirty electricity system and our tank and bio-ball filter are at 26 C. happily chugging away. It's 9 pm and we push some of our water out to the beds ( Floating raft beds in on insulated container.) Let's assume that said insulated container has not been fed 26C water for 2 hours and its temp has dropped to 20 C . The floating raft bed has a area of 1.5 metres wide and 4 metres long ,, it is 30 cm deep ,, so approximately 2 cubic metres of water. One needs to be gentle with fish in regard to sudden temperature change ,, so lets say we use a smallish ( by this forum's standards) pump for 10 minutes and moove 500 litres of water ( a quarter of the floating beds volume ) .

Law of nature says 2,000 litres sitting at 21 C ,, add 500 litres at 26C , temp will settle at about 23.5 C in the grow floating raft bed.
Flow back to the bio-filter is 500 litres of 21 C water , boi-filter initially has 1,000 litres at 26 C , so water temp drop to24.5 C envisaged ,, but that water is quickly exchanged with grow tank ( remember the grow tank and bio-filter are in the same shed and at same temperature) .
So the 24.5 C of the 1,000 litre bio-filter is quickly exchanged with the 3,000 litre 26 C grow tank. RESULT about 25.5 C.
So , first cycle complete and a mere zero point 5 temp loss , ( in theory).
Aeration of the bio-ball filter is continuous ( can't have our little green mates running out of oxygen).
Un-accounted losses will be in pipes , plant expiration ( spelling? ) etc .

So now , what is the cost of replacing that 0.5 degrees in 6,000 litres of water 6 times per night.
( power requirement will be inheritantly less in the day-time so will need a different calculation)

Wanting to get the heater figure REAL ,, I just added 2 litre of 17C water into a normal submersed eleement jug. The jug is rated at 2000 watts .....................
It took my jug 300 seconds to boil . Thats 2 kilowatts applied for approximately 1 twelth of an hour , resulted in 2 litres of water raised in temp 80 degrees.
So 0.17 kilowatt hours raised 2 litres 80 C
So , 1.7 KWH would raise 20 litres 80 C.
So 1.7 Kwh WOULD raise 2,000 litres 0.8 C
So 1.7 kwh would raise 6,000 litres about 0.27 C ,, we need double that

We needed to heat 6,000 litres of water one half of a degree , so double 1.7KWH is.....
3.5 KWH ,, is the required usage ....., 3.5 times 6.8 cents

24 CENTS,..... that can't be correct? ??????
24 cents per NIGHT , to keep your fish and plants at maximum growth.

Even though day time temps are better lets add a further 24 cents.
So less than 50 cents a day keeps everything happy .

I think the major problem has already been mentioned. The warm system is fairly straight-forward. The cold system is where the issues are.

How well will the plants be growing in the shade?

How much bacterial activity will be occurring at the low temp?

Both of these directly impact how many fish you can put in your cold system.

edit:

And seed germination & root development are highly dependent on soil (gravel) temp.

Hi Chappo
Your insulation is predominantly a radiant barrier, it is designed to reflect radiant energy preventing it from entering the building.
Using it in reverse may help reduce the radiant loss but its not much help if the predominant modes of heatloss are from convection and conduction.

Wrap a bucket of water in aluminium foil (shiny side out) and it`ll stay reasonably cool in full sun. Then see how well it does at night, turn it shiny side in and create a 1" airspace between the bucket and the shiny side. The airspace being the only thing slowing the convective and conductive losses (R-1.2 - R-1.5)

(I'm not entirely sure of your climate there but...) I'm guessing you might be able to take care of much of the warm system issues in cool weather using some cold frames or minimal greenhouse structure that would probably double as shade support in summer. (at least that is the theory I went with on my system.) Anyway, couple your insulation around growbed bottoms/sides and piping along with something you can throw plastic over for the worst of the cold weather and the warm system is probably good to go.

As everyone keeps saying, the cool system is more of a challenge if you have really hot summers. Plants that do well in shade are not usually heavy feeders which would mean you need lots more plants to do the job so you need more grow bed or NFT going which is more to keep cool......... Hum, cheap ways to chill water???????
One idea I had for my system to help keep gravel cool if it wasn't well covered by plats was to use spanish moss kinda as a "mulch" over the gravel around the plants. It makes a fairly good moisture retaining mulch around soil plants and I can get lots of it around here for free! I don't know if you have anything like it there though.

Couple of possibly significant flaws in your design Chappo...

If you intend running "Floating raft beds in on insulated container"... then by definition, and requirement, you'll need to be running them as a UVI style DWC system....

i.e .... constantly flowing, possibly oxygen supplemented.....

This alone will mean a constant flow back through the other components of your system....

If you have a constant flow through your system, then I think that the temperature will equalise through the system components much more rapidly and drop significantly more than you hypothesise......

Maybe.... just maybe you could get away with switching them off for short periods... don't think anyone has done so..... and all the systems that use this method definitely use a continuous high volume flow with a significant surface area of floating rafts to partially provide a media for bacterial attachment...

You are relying on your primary bio-filter to provide not only the filtration for 3000ltr of fish tank volume, but also to remove the solids from your water before pumping to your floating raft beds.... a necessity in this style of system....

I'm a little confused as to the size of your bio-filter... at one point you say "a half a cubic metre" .... which is 500ltr.... but later refer to it as 1000ltr...



Assuming it is in fact 1000ltr ... then you will be exchanging 1000ltr from your floating raft growbed to your fish tank (50%) .... and then 1000ltr (33%) from your tank to your bio-filter.... and then back to your floating raft bed...

Your beds you quote as approx 2000ltrs.... so you will be returning 1000ltr (50%) back to your beds each time you pump.....

I think this probably significantly alters your projections and hypothesis.......

If you only pump 500ltrs... as you first suggested... then obviously those figures are halved....

I'm not sure what you mean when you say ....



I'm assuming you are referring to your ffloating raft growbed...... if you are then I'm not sure how you arrive at the figure of a drop from 26 degress down to 20 degrees... assuming your first pump cycle kicks in after only a two hour "off" period... regardless...

If your Jades (possibly 100 of them in 3000ltr tank).... are running at around 26 C during the day, then they're probably all growing rapidly and feeding/respiring to their maximum at that temperature.....

Sorry mate but 2 hours of not pumping IMHO, will probably kill them...... probably through lack of DO.... possibly because of an increase of ammonia...particularly if you system is running at a pH around 7.5 - 8.0.... and with temperature fluctuations....

Then you're expecting to process your ammonia load (produced by 2 hours of not pumping).. through your bio-filter and floating rafts in about 10-20 minutes of pumping and only exchanging 33% of your volume..... then you shut down you pumping for another 1.5 hours???

P.S....



The action of continuously aerating the bio-filter will continually break the surface of the water in the bio-filter with the bubbles and draw air/oxygen down into the bio-filter... hence not only oxygenating the bio-filter (good) but setting up a circulation of the water....

Drawing air into the bio-filter.... albeit from an insulated shed.... will in itself tend to lower the water in the bio-filter to at least the temperature of the air in the shed... surely??

Think you've made both some assumption and oversights in both your calculations and system design Chappo..... what do others think ???

To summarise further....

You're only going to be processing 33% of your ammonia load every 2 hours.... therefore potentially, 66% of the load will remain unprocessed in the fish tank... and the fish will continue to add to the load...

Granted you've introduced 1000ltrs of "clean" water in that period.... a dilution factor....

But IMHO.... you'll not be turning over your tank volume... hence processing your potential full ammonia load, sufficiently...

Your ammonia load will increase cumulatively and ultimately exponentially... to the point that it will become detremental to your fish..... will this occur over night.... maybe... maybe not...

Assuming that it doesn't exceed limits.... it will probably at least stress the fish... leaving them vunerable to secondary infections like fungi and bacteria...

Further... you're then relying on the bio-filter and growbed rafts to process the ammonia and uptake the nitrates during the daytime cycle....

Add the stress of temperature fluctuations when you pump during the night.... fluctuations of pH due to ammonia buildup.... fluctuations in DO, both due to normal processes and pumps being off ..... all processes dependant and relative to temperate and pH...

I really do think IMHO.... that your fish will struggle... possibly die

Thanks all for the interest , comments , questions and ideas .
I wrote a long nice reply during a quiet period at work last night then hit the wrong button and lost the lot

Tamo42 , Temps should be ok , Sydney has very mild winters , I believe it did snow once on SYdney but that was some 50 years ago. 6 Celsius ( 43 F ) is our usual minimum air temp and soil temp 14 C ( 57 F) .
Reflectors for light will assist somewhat ,as will growing low light tolerant plants ,, lettuce , parsely etc and the back of the bed will have lattice for climbers to grow into full warm winter sun.

Hex ,, yep you read my mind ,, already planed on putting batt type insulation around tank and then the matt type over that. Got plenty laying around as I'm doing a house extension. Hopefully I can run that bucket test tomorrow night,.....,,

TCLynx ,, very mild winter here , a temperate/sub-tropical climate.See above for temps.


Rupert ,, you've got way too much time on your hands:) Good points raised and I hope I can answer a few and then get more feed-back .

Rupe ,, I see no reason why the Floating beds need constant flow , or to be particularly deep.
Is there a reason ?
I purchased some seedlings a few weeks back , haven't got round to planting them ,, they have been sitting in a container of water , no oxygen added and just a top up each few days as water evaporates. The plantlings seem reasonably happy , so i see no need to use large constant flow for either oxygen needs nor nutrient needs. Remember the water added on the last pumping before the cold of night sets in ( say 9 pm ) will fill that raft area with nutrient and oxygen rich water , they only need survive 8 hours at max. ( then next pump-out / in occurs). If needed small amounts ( 500 litres) could be added on regular intervals during those 8 hours.

AHH you got me on the bio-ball filter , I was thinking 1,000litres and also surfing the net for prices at the same time ..... SHEESH 1 cubic metre od bio-balls is a LOT of BALLS and a LOT of money:) Hence reduction to 500.

Pumping to the bio-filter ( in warm shed and insulated) will be on a continuos basis. It is only the supply OUT to the grow beds that is turned off OR highly reduced at night. So that bio-filter must be able to cope with the fish output during the Plant bed NOT pump times. I'm used to doing calculations using feed input , rather than number of fish etc ( although one is used to calculated the other) .Assuming 100 baby fish at beginning , I would guess maximum system load would be at around 6 months from then. 10 % dead , 10 % runts , 20% fast growers and 60% in middle range.
10% dead weight nil
10% runts maybe 150 gramme X 10
20% fast 600 grammes
60% middle , average of these 400 Grammes.

Total max fish weight , 37.5 KG , lets make it 40 KG.

3% of body weight as feed would be average for most fish at this age. ( I do not have trout specific info on this as yet)
So input is 120 grammes of food per day.

The Kaldnes type system is rated on several sites as capable of coping with between 1.5 kilo and 500 grammes of feed per 100 litres of material. I believe that problem solved.

The air being pumped into the bio-filter is from within the warmed shed , also do not forget water has a very low thermal mass. The warmed air would also tend to condense on the under side of the FT cover and the water drop back in. I doubt very much this would cause much temp loss , but will add that as another thing to throw an experiment at.

Thanks , and please keep the ideas / thoughts / questions coming.

Yep, possible root rot problems.... there are other members that switch their pumps off over nite.... but they're utilising flood and drain growbeds.... so the plant roots aren't submerged in water, paricularly the lateral oxygen uptake roots.....

Might get away with it Chappo..... just most systems of that style have proven to be most successful when run continuously with good flow and oxygenation.....

Depth.... well flood and drain has proven to proform best with the recommended 300mm.... partly for volume of bio-filtration, partly for oxygenation, partly for plant support...

Floating raft.... well it could be done in a shallower depth.... a lot of hydro trays, even those that utilise a "flood and drain" style, are only 100-150mm...... but again they tend to be run continuously.....

If you go too shallow, particularly when your plants are fully grown or growing vigourously... then the plant root systems will be extensive....

With a shallow depth it's possible they may intertwine and matt throughout the whole growbed.... this could lead to "channeling" of the water.... some spots holding water and developing root rot... other spots remaining almost dry.....

Remember even hydro NFT requires a continuous flow to be effective....

Try it and see I suppose....



Ahhh.... a little bit of information goes a long way..... obviously this alters and addresses the issues of bio-filtration and oxygenation of the fish tank...sufficiently???

Will 500ltr be enough??... well the Kaldnes are certainly rated as such.... how/what do you envisage using as your your bio-filter.... any chance of a pic or drawing?

I have heard that an alternative to bio-balls for a bio-filter, is the use of the plastic caps from drink bottles.
Perhaps this would help reduce your bio-filter cost.
Here's another idea, why not use well washed gravel or hydrotron and just not plant anything in it. Although planting is possible, unless you have adequate light, there is not much chance of survival of any plants in the bio-filter.

Tony

Quite a few people run bio-filters using those media (gravel, hydroton) ... or even oyster shells.... works well.....

My glasshouse system is currently running sort of seperate from the main system and theres 4 1/2 beds[ones 3 in deep ] one bed is scoria for fish water [bio filter watt ever] then drains to sump then theres a small pump that runs 15 min every 2 hrs to the 3 1/2 beds this is running with a top up if fish water 10 litres every hr atm the system outside is 10 deg, inside system is 15 deg and i havent turned the heater on yet so to sum it up in my systen realy the only things bennifiting at the moment are the plants in the glass house

You are a nob of pri;'s putting ideas into a blokes head from the time i put in the last post [7.30 am ] i have taken the side out of the glass house leveled the floor and draged a 1000 litre tank ready to go in [just waiting for son ] so when finished i will have 2 systems one hot one cold
The hot system will be 1000 litre fish tank [with viewing window ] 200 litre sump 4 1/2 grow beds all running shift pst all heated with nat gas [will post pickies tonight]

Heres pictures [lessons learnt wait for son ] dont ask the wife to help especialy when you swear at her [she dropped it on my foot]
You will notice the cabbage and collie a bit droopy i folded up the shade cloth cover and left the door closed [while i had my nanna nap ] the temp got to 48 deg