Murrays System

[Murray]

My first system was based on a 250 ltr FG rectangular tank.
I started out not knowing anything about fish and my first 100 Jade perch fingerlings lasted all of 72 hours. Very sad, but I learned fast about fish.
I made for the system a crude but very effective bio-filter. I employed a 300mm dia plastic plant pot for this purpose.
It can be seen in one of the photos below.
Because of my boating background I was natural for me to want to use 12 volt DC pumps that I hoped to run off solar panels etc.
I quickly found that the pumps that are available (at the lower cost end) do not last long. Some burnt out after only a couple of weeks and others after 3 months. I made the switch to 240 volt pumps. I did the eBay thing and got the cheap "yung-flung" brand pumps. Some of them were ok, but I had a few too many failures.
Don't waste money on rubbish pumps. You get what you pay for in pumps, I can tell you.
The plant pot bio-filter was filled 3/4 way up with 20mm gravel and the top bit had fiberglass insulation material in it. The flow rate of the water going in was regulated so that a good proportion of the water spilled over the side into the fish tank thereby providing aeration. The balance of the water found it's way down through the filter material and out of the large slits in the bottom of the pot.
I just love the photo of those little Jades peeking out from their hide, which is a piece of 90mm PVC pipe.

[Murray]

My Aquaponic system as it was on 22 December 2006.
It is really starting to get a move on. Great plant growth.
It is just astonishing how well plants grow in an aquaponic system.

[Murray]

Today I got a crude solar heater going on the shed roof. It is just 50 mtrs of 19mm black poly pipe laying at random on the shed roof. It managed to raise the water temp in the big tank by 4 deg over the day.
I think it also got some help from one gravel grow bed that is not in the greenhouse and is planted with Sugarloaf Cabbage and Broccoli.
Anyway, I am pushing ahead with the corigated iron type which I believe will work really well.
Murray

[Macca]

Have you estimated how much electricity you used to do this? How much does your tank notmally heat up during the day - quite a lot of the 4 degrees may not be due to the hose.

[Frank]

Good point Macca. I hadn't thought of that.

I guess Murray must be pumping it through the 50mtrs of tubing.

Is it easier to pump through 19mm tubing and wont it block up?

Murray what sort of pump are you using to do this and how much power are you using?

Would it be cheaper than using those 300w aquarium heaters?

[Murray]

Macca, Frank,
I am using a 300 watt submersible (Italian made) it moves 8000 lph at no head.
I run the pump all the time through a small bio-filter and I have made up a very untidy temporary bypass of that to the roof pipe. So during the day I divert the water from the bio-filter to the roof and choke the flow back to not much more that an trickle. The water coming out of the end of the pipe is a fair bit warmer than when it goes up to the roof. I will have to measure the temp difference today.
I still feel that the corrigated iron thing suggested in the other thread will work much better than the black poly pipe. Perhaps the black poly pipe would be good if I had about 300 mtrs of it....but then the cost of buying the poly pipe.
I am possibly using a little less power than a 300 watt heater because the pump is not working to it's full capacity, but the difference, if any, is not worth worrying about.
I can't imagine a 300 watt heater making much difference in a 2000 ltr tank, but it might do the same work for the same number of watts. It would be an interesting discussion... Perhaps some of you science heads will know the answer to that one.
I am sure the one gravel grow bed that is outside in the direct sunlight is helping a bit.
Muzza

[GaryD]

Hi,

I'm using a 300w aquarium heater in 650 litres of water.

This morning, the ambient temperature is 7 degrees C and the water temperature (inside my unlined shed) is 14 degrees C.

It's moot point though because I'm still six degrees below the temperature at which my Jade Perch will eat properly.

Gary

[Murray]

The water temps today were as follows.
At 7:00 am 17 deg
At 5:00 pm 19 deg

The flow from the poly pipe on the roof was going up to the roof at 17 deg and coming out into the tank at 22 deg. But a very small flow as can be seen in the photo attached. I just wonder about the poly pipe on the roof if it is making any difference at all. So tomorrow I will not run it at all and see if there is a difference, if there is a temp rise during the day.
Muzza

[Murray]

Gave up on the Solar thing on the roof, it does help but not by much. I have 6 big Jades in a 230 ltr header tank sitting atop my big tank and they are not doing so well in the low temps. Yesterday I made the trip to the Aquarium shop and paid out the dosh on a good quality heater for the poor mongrels.
It is a "Hydor theo 400w" It can actually be totally submerged , lay it on the bottom on it's side if you want to. (see pix below)
Cost 80.00.
I set it to 26deg , laid it on the bottom of the tank and let it do it's thing. Put the lid on the tank for the night. This morning, check the water temp and it is a solid 26 deg. The Jades have taken on a new vigor.... Jades really do not like cold conditions.
Meanwhile the Silvers I have in my big tank are doing it a bit tough...water temp 16 deg this morning, but they are ok. They are not very interested in the pellets at the moment but chop away steadily at some lettuce leaves floating in the tank. Trouble is they will not grow much during winter with such water temps.
Muzza

[Jimmie]

That heater is very interesting, I thought that the heater would need the top of it, the temp control part, to be out of the water. Being able to completely submerge the heater would make it a bit more efficent.
Also, how are the fish in the heated tank going now that they have been warmed up for a day ot two?
Jim

[Murray]

The Jade Perch are back on their food again, which is very good.
They were not eating at all while the temps were right down. It is interesting to see how slowly they move around when the water is cold. I could reach into the tank and actually touch them before they moved away. Now that they are warm they are swimming about briskly.
They are chopping away at the lettuce leaves I have just thrown in to the tank.
And the heater is lying on it's side in the tank. The packet instructions clearly say it can be laid down in the tank...see the pix from the side of the packet.

Murray

[Frank]

Are you, or will you be running the heater continuously?

How much power do you think you might use, say each month over winter?

[Murray]

Frank, I will just run the heater until spring. It is in there on all the time, but I have the tank covered so I guess it is not doing much now that the water is up to temp.

Muzza.

[Macca]

If the heater is just in your small tank, what is going to happen with the other fish. Will they die?

[Frank]

If the heater is just in your small tank, what is going to happen with the other fish. Will they die?

How many tanks and fish do you have Murray.

Can you post some pics of all your system for an overview and step us through what each part is and does?

[Murray]

I have the loan of an immersion heater which I ran for several hours yesterday to try and bring the temp up in my big tank. It is 2400 watts so it will make the meter spin a bit.
I ran it for 4 hours and it brought the water temp up from 14 deg to 19 deg.
Last nightI covered the tank again with a plywood sheet I have cut to fit, and turned off the main pump that moves the water to the grow beds.
The temp dropped 1 deg overnight.
Today I will run the heater for 2 or 3 hours and see if I can get the temp up to 22 or 23 deg. Then I will see just how long I have to run the heater each day to keep the temps around the 20 deg mark.
A couple of pix below of the heater. The bubbles are from an air stone that is on the bottom below the heater. (not the water boiling)

[Murray]

Here is a photo of my Cabbage and Broccoli.
Broccoli in the front two rows and a row of Sugarloaf cabbages in the background.
I had some caterpillar attack when the plants were small, but I have been spraying weekly with a weak Seasol solution and it appears to be working well.
Sugarloaf cabbage is a particular favourite of the bug world, so this will be a good test for natural control using Seasol.
Muzza

[Macca]

Gotta find a better solution than that. One of my reasons for being interested in aquaponics is its sustatinability. Running such a power hungry device really isn't practical aquaponics (excuse the pun).

[Macca]

Where did you borrow the heater from Murray. What is it normally used for. Is it just like a big kettle element?

[Murray]

Yes Macca, I agree, it is not a very good solution to the heating problem, but it will get me by until I have time to do something better like the solar suggestions in another thread.
I have been going to do something all summer long, but left my run too late.
Last winter the heating was a problem as well, but then I had my fish in a smaller tank so 1 x 300 watt heater was able to control the cold.
Silver Perch are pretty tough and they would have been ok in 14 deg water , but they don't eat much at that temp and therefore don't grow or produce waste for the cabbages.
And the big heater is in my 2300 ltr tank which has about 2000 ltrs of water and 300 Silvers in it at the moment.
Most of the Silvers are small fingerlings together with 3 big Silvers over 1 kg each.
Muzza

[Murray]

Yes Macca , it is a big kettle immersion element commonly used in manufacturing plants etc. I only have a loan of it. I really don't like using it, but it is better than nothing. I will have to make sure I don't get caught next winter with the same problems.
Muzza

[njh]

Yes Macca , it is a big kettle immersion element commonly used in manufacturing plants etc. I only have a loan of it. I really don't like using it, but it is better than nothing. I will have to make sure I don't get caught next winter with the same problems.
Muzza

Almost all your heat will be leaving in the form of evaporation. If you can seal the tank down to say a 1cm sq hole you'll reduce your heat losses dramatically. If you are using an air stone, then the amount of air you need to vent will be as much as the air stone is putting in. The amount of oxygen in a 20cm void at the top will be maybe 100 times more than all the dissolved oxygen in a 1m of water below.

I'm putting 4 C worth of heat every day, and every morning it has all literally evaporated away - my greenhouse is absolutely soaking in dew, on the inside. In that case I know that for that water to condense, the same amount of heat must be being drawn out through the glazing. Double glazing would help a lot, as would sealing my tank more.

[Murray]

NJH,
Adding the lid to the tank makes such a difference. The result is very much in line with what you have suggested. I only leave a very small hole about 100mm square.
Most of the heat loss is from the water surface, that is for sure.
I have dozens of old sheets of roofing iron stacked up in the paddock, so I will be making a solar heater along the lines you suggested in one of your earlier posts....soon....
I do hope you will keep in contact with the forum while you are over in "yankee land"
Muzza

[etacwa]

Correct me if I am wrong but would it not be better to grow fish that are temp suitable?
Doesn't seem very sustainable if you have to pump heaps of energy into them!
Sorry if that is a rude .

[Murray]

etacwa,
no that is not rude.
Silver Perch are very suitable to my area, but....if I want them to keep feeding and keep supplying nutrient to my grow beds, then I need to keep the water to summer temps.
In their natural state they slow right down in their activity during winter.
Murray Cod are able to better tolerate low temps, but they also slow down when the water temps are low.
I need my tomatoes all year round.
Muzza.