Backyard Aquaponics

Aquaponics in a school setting
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Author:  Sunrise Girl [ Nov 19th, '06, 06:49 ]
Post subject:  Re: Aquaponics in a school setting

MCPHRO wrote:
250 lt/h - $12.99
750 lt/h - $12.99 -
950 lt/h - $24.99 - Dont know why its cheaper?
3300lt/h - $100.00

400Ltr compost bin (fish tank) $ 75.00

It didnt seem to have any holes but is there a problem with black plastic?

Black poly tubing $7.16 for 20m * 19mm tubing... Same question as above.

Hi Roy,
I have one of those 250 lt/h pumps and, to save you $12:99, it's supposed to be good for .6/mt head but it's not coping with it...
Black plastic has a possible issue for water heating? Gnash (i think) had black pipes that turned his system into a hot water service *outdoors*, you're setting up inside so it shouldn't be an issue.

Author:  MCPHRO [ Nov 19th, '06, 11:38 ]
Post subject:  Re: Aquaponics in a school setting

Over what time period should enough water be taken out of the tank to replace all the water? I mean, if I had say a 700ltr tank, and the pump pumps 250 lt per hour, then in a 3 hour period the entire tank would have been cycled through the growbeds... Is that right? What flowrate shoulld you use. Also if you were replacing that much water, is there anough time for the fish to pee in it, nutrients to build up etc?


Author:  steve [ Nov 19th, '06, 11:58 ]
Post subject: 

correct on the water exchange rate. minimum conensus is one tank volume per hour, with mst people preffering two per hour.

Don't worry about the time for fish to pee in it, and water contact time with the gravel. IMHO trying to visualse a "snap-shot" of the process doesn't work as its a contiunous process. Regarding "contact time" of the ammonia to the bacteria (it been brought up before) my example is to look at a cannister filter for an aquarium. The have huge flow rates, the cannisters water is probably changed in 10-15 seconds, yet it works great. Its a contiunous process, can't look at it in "batch-mode".


Author:  MCPHRO [ Nov 19th, '06, 12:09 ]
Post subject:  Re: Aquaponics in a school setting

so steve, there should not be any problem with me setting up a system where the entire amount of water is changed every hour (so for a 700lt tank buy a 750 lt/hour pump) and keep the roots wet in the growbeds at all times and long as the pump keeps going and keep the flowrate up?

So a 700 lt tank pumping 750lts per hour through the growbeds with around 35 - 40 fingerlings.... so im wondering about the growbed size. If indeed that the growbed depends upon the amount of fish you have...

Does this mean...

1. I should plan to start say with 1 * 2m * 1m growbed and as the fish get older and larger(and PH goes up) add another growbed?

2. How will I know when I have enough nutrients for each growbed, enough to sustain the whole bed, or when to change to add another growbed.

3. If I had too many nutrients... just grow pumpkins... is that right :twisted:

Author:  steve [ Nov 19th, '06, 12:16 ]
Post subject: 

First thing to watch out on is the flow rate of the pump, if it quotes 150 lph then its basically pumping horizontal with ZERO restriction. As you increase the height the water has to go, the flow will drop upto the height the pump is rated at (eg 3m) at which point you will have ZERO FLOW.

Very easy to get caught out thinking a 750l/h 3m head pump will flow 750 l at 3 meter. Not on your life. The pump manufacturers have nopt heard the "can't have you cake and eat it too" line ;)

I'll leave your second question for joel to answer, as i'm feeling a little inadequate, as i'm having major system issues and don't want to lead you up the back yard aqua path ;)

Oh, and its NO3 (nitrates) not PH

A nitrate test kit will help you with your nutrient levels.


Author:  johnnie7au [ Nov 19th, '06, 19:10 ]
Post subject: 

Hi McPhro

A good source of equipment is by letting people know what you are trying to do.

My school just had 60 fish tanks donated for a fish room we hope to get together during 2007.

Author:  Jaymie [ Nov 19th, '06, 19:22 ]
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how big is the room? wow! that's great Johnnie!

Author:  aquamad [ Nov 19th, '06, 19:27 ]
Post subject: 

Sure is great, wish you were on our staff :mrgreen:

Author:  johnnie7au [ Dec 26th, '06, 22:29 ]
Post subject: 

OK .. now I am going to beg here too!

I have absolutely no scruples when it comes to begging on behalf of my students.. hee hee ...

I would even cook you lunch in my speedo's .. EEEWWWW! :shock: :shock:

OK forget the speedos ....

OMG ... EEEWWWWWW! :lol: :lol: :lol:

(Well , I would cook your lunch on the hotplate or the oven ... not actually inside my bathers!) :oops: :oops:

(That lame gag must be worth a compressor that is lying around in someone's shed!)

OK .. here is the progress regards the school Science and Agriculture department upgrades ...

The walls are going up on the new farm building and Ag. Science lab area and good progress on the two new physical science labs.

OK .. progress report over .. now for the begging bit!

I am hoping to have access to a dedicated secure area in the old animal shed. It will need plumbing, drainage and electrical services.

It must be locked for safety reasons.

However, pupils with responsibility will have access, as would our primary school visitors and any student under supervision of a teacher. (This avoids little fingers banging on the glass, adding chewing gums and biros, pulling out air tubes etc. etc.)

I am just trying to work out some plumbing.... for the "fish room" I have in my head!

Aside from setting up a few independent tanks in classes ... I reckon my school could do with a brilliant fish room!

Members of Perth Cichlid Society have donated an amazing amount of aquariums, equipment... and fish that I and others are holding over the Christmas holiday.

Now all I have to do is to try and bring it all together .. and I don't want to let anyone down... this is so scary!

I think I am going to need to find a BIG compressor to service the whole lot. (Any ideas where I could get a really big (quiet) reliable (bombproof) compressor that could service 50 or so tanks for 30 years ... and their sumps?) - I guess we are talking about 3 - 400 dollars for something that would provide the output and the pressure and be fairly quiet..

Personally I am happy to beg, borrow, contribute .. whatever! (Forget the speedo thing ..) .. :oops:

I think that I need to arrange the tanks in separated banks .. say 4 or 5 or so small tanks per sump or one tank per sump if it is a large tank.

Each class being responsible for its own set (bank) of aquariums.

(Sumps would be made from old wheelie bins). (Amazing resource for people who keep fish).

Each tank has its own air line. Each sump has its own air line and an air-lift gravel filled bucket filter system and a pond pump for recirculation through each bank of aquariums.

Flood and drain aquaponic growbeds for converting nitrates etc into vegetables and herbs could be plumbed into the sumps independently at a later date by adding pumps and gravel filled plastic trays supported on bricks.

Any ideas?

Anyone have a really mean quiet compressor lying around in their shed doing nothing?

I hae not even thought about lighting yet .. Will need some advice on that one for sure!

Regards the sumps .. I have acess to a plastic welding machine and could lay in dividers etc. Anyone have any ideas on what makes a good sump?

Best to ya all,

happy holidays to you.


Author:  steve [ Dec 26th, '06, 23:07 ]
Post subject: 

johnnie, i reckon you should go for a centifugal blowerfor your air supplies, it will be more effcient, more quite and probably last longer.
I didn't even realise the one at minnamurra was switched on!

They run at between 7 and 10 kpa which is all you need.

Downside i guess is that there is no intrinsic backup, but for the supply you're using, a compressor tank aint gonna give you much backup time anyway.


Author:  aquamad [ Dec 26th, '06, 23:23 ]
Post subject: 

DAng, wish i could help you out! That is one hell of a 'bring together' you have to pull off there :shock:
Have you looked at the opp shops?

Author:  johnnie7au [ Dec 26th, '06, 23:41 ]
Post subject: 

We got a grant for solar electricity system ...

now even a 5 hour battery back up or inverters .. would be good .

Have to cross that one about power outage when it becomes important .. :wink:

(What do aquarium shops do? Do they all have back up power?)

(Visions of teachers giving CPR to fish!)

My main point is getting air to service all the tanks ...

I think centrifugal is the way to go ... I just got to get one given to us! :wink:

Who wants my speciality, speedo fried fish and chips? Anyone?

Cost ya a centrifugal pump! :oops:

Author:  aquamad [ Dec 26th, '06, 23:43 ]
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*aquamad runs off screaming into the distance after picturing it*


Author:  johnnie7au [ Dec 26th, '06, 23:45 ]
Post subject: 

The things we do!

Hee Hee!

U want fries with that?

Author:  aquamad [ Dec 26th, '06, 23:53 ]
Post subject: 

*gag gag gag*...
if you teach, its part of the job

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