Backyard Aquaponics
A place to discuss aquaponics

I noticed that. Damn, was gonna comment but forgot LOL That's a very pleased fish!

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www.thefishfarm.com.au

He still hasn't noticed the BBQ, that would knock the smile off his face!

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Erik XIV

As far as the "magic" 2:1 ratio for growbed:tank volume I'm not quite sure about something. Is the reason it is important to have the larger growbed to 1. filter solids, 2. increase the surface area for bacteria, 3. more area for more plants to suck out the nitrates, 4. all of the above? I was guessing that even a relatively small volume of the biofilter/growbed (say 0.5:1) would be big enough for the bacteria to do the job, but wouldnt hold enough plants to remove the nitrate. I was hoping the plants in the nft would do that instead. Or do you think I actually need more surface area for bacteria? Are there other ways around it eg. use smaller medium in the filter to increase the surface area? Really I'm looking at maximising to fish stocking, but not to extreem levels. Yes I will be trying to throw in an extra growbed but am interested in your thoughts.

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Erik XIV

KE, IMHO, the answer is 4. The more biofiltration, the more fish. And yes, the more gravel beds, the more plants, the more nitrates taken out of the water, the more you can feed, more fish!. And you are right, the plants in your pipes will do the same job. I'm sure there is equations for how much biofiltration you need to have with separate biofilter. Maybe a smaller medium would be more likely to clog? Are you going to run the pump all the time?

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www.thefishfarm.com.au

IMO - you are correct in that it is the nitrate removing capability that requires such a large surface area of grow-beds. Of course the 2:1 is only indicative and will depend on a heap of other factors such as the plants being grown, the feeding rate etc.

Theoretically some NFT or DWC should be able to be employed to supplement gravel beds that are acting as filter, gow medium and bio-filter. A lot of us here want to play with this type of technique, though some have not been having great success with the DWC part of their system - possibly for reasons easilly fixed.

Stu - beat me to the punch.

VB .... am looking to utilise some nft to supplement my grow beds.

Was thinking I'd place these before the growbeds rather than after... rationale at the time was to give them first bite of the cherry as far as nitrates were concerned and because I was looking at strawberries or similar which are heavy nitrate suckers.

Jist I'm getting though from recent posts is that the nitrate levels don't vary over the entire system, so it doesn't really matter where the nft is positioned in relation to the growbeds.....

Just then leaves the question of whether or not to place the higher nitrate feeders first. Any thoughts???

Hi i think its best to place the nift after the grow beds then you wont get solids sticking to the roots i am shore others will tell you the same thing

I agree.

my 2 cents on the 2:1.............

I believe its both for the solids removal and to allow sufficient plants for NO3 removal. I think that the bacteria are in a very spacey home indeed

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The only tool you need is a paperclip

Grow bed before nft sounds nice. i did it once but encountered problems with water flow. it just wasn't moving fast enough.

To counter this i used a 3in pipe half fill with shade cloth as the filter it should do the job. It has to be a continuous flow system because it traps the solids in the un-stuff end of the pipe and keeps them there constantly moving around, like a fluidized sand filter so the bacteria actually colonize the surface of the fish poo instead of gravel or what not.

I am yet to put in any plants but it i can tell you it takes out all the solids and shouldn't clog, ever, because of the way it works.

Plus i could have my pump at full blast

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I got bad syntax.

I hear you CG, but I not sure I'd want to trap all the solids in the nft if I was then running onto growbeds, although I guess the water is still nutrient rich, I'm assuming that the growbeds require a certain amount of solids to maintain the viability of the bacteria in the growbeds.

So I'll probably put the nft after the growbeds, working on the reverse theory that...

(1) nft rally ony requires nutrient rich water

(2) if majority of solids have been removed/deposited into the growbeds, I shouldn't suffer from any solid build up around the root balls of plants in the nft

KE14 are you up and running yet?

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Unattended children will be given an Espresso and a free puppy


http://www.backyardfarming.com.au/phpbb ... f=24&t=270

Almost.
I ordered my fishtank to be made by a rainwater tank mob back at the start of December, and they told me I should have it by Xmas. It's half made now and I'm hoping to pick it up on Thursday. Everything else is mostly ready. Unfortunatly I cant fill up my pipes with gravel because they sit over the top of the tank, otherwise I could have rigged up a small temporary tank and started circulating some water.
Monyas got my fish now and I'm just busting to get it all going ...

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Erik XIV

Apparently patience is a virtue

( can't stand it myself )

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Unattended children will be given an Espresso and a free puppy


http://www.backyardfarming.com.au/phpbb ... f=24&t=270