Aquaponics System Design

[John Malone]

Hello All,

I'm about to launch into building my AP system here in Phoenix AZ.  

Here is my current system design.

I'd really value any input, comments, criticisms and suggestions before I take the plunge.

The fish tank will be sunk into the ground by 12-14".

 

Regards,

John

[TCLynx]

I don't know if a sand filter is really appropriate for you.   A pressurized sand filter is going to require a big powerful pump to really get much flow through it and a slow sand filter will likely only take a trickle through it and both will still require regular maintenance. 

 

Seeing as it looks like you will have media beds, I would say skip the extra filtration and just let your grow beds do the work (though if you want a heavy fish load you may need to add more grow beds and if you can't do that, you might be better off designing a swirl filter so you can simply remove some of the extra solids.)

[John Malone]

Thanks for the reply TCLynx. The bucket in the design is a swirl filter to be built as described here: http://www.ecofilms.com.au/2010/08/20/diy-swirl-filter-for-aquaponics/

I agree, a sand filter is outside the scope of this backyard system.

Cheers

[TCLynx]

I can see where a swirl filter could be worth while if you are going heavy on the fish and staying minimal on the grow beds, provided you are around most of the time to check it and clean it.  I actually like the low maintenance side of just letting the gravel take care of it all.  I had a swirl filter for a while (but it wasn't well designed and the flow rate through it was too fast) but it still collected solids.  Unfortunately, if it wasn't emptied of the excess solids like every other day, the stuff got really anaerobic and the smell upon emptying it after three days or so could gag a vulture and I usually have a strong stomach for yucky stuff. 

[John Malone]

Thanks for the heads up TC,

I'm still a bit 50/50 about the swirl filter.   It seems like there are two opinions on this in the AP world.  The purists, for lack of a better word,  insist that for long term health of the grow beds a filter is necessary.  The pragmatists tend to accept the fact that the grow bed may need refreshing every 5 years or so and enjoy the simplicity of no filter.

 

I am torn between the two camps, as I like the idea of doing something 'properly', but realize that it's highly unlikely that I'll have this exact system in 5 years anyway, so why complicate matters....    AP seems to be a tinkerers dream (or nightmare, depending on the results) and I expect there to be many variations, additions and redesigns as time goes by.

 

Thanks for the dialogue.  I appreciate the discussion and feedback.

I'm still in design mode and changes are just a click of the mouse....

 

Regards,

John

TCLynx said:

I can see where a swirl filter could be worth while if you are going heavy on the fish and staying minimal on the grow beds, provided you are around most of the time to check it and clean it.  I actually like the low maintenance side of just letting the gravel take care of it all.  I had a swirl filter for a while (but it wasn't well designed and the flow rate through it was too fast) but it still collected solids.  Unfortunately, if it wasn't emptied of the excess solids like every other day, the stuff got really anaerobic and the smell upon emptying it after three days or so could gag a vulture and I usually have a strong stomach for yucky stuff. 

[TCLynx]

Another thing to add to the thought basket here is that most clogging of grow beds I've seen, had far less to do with the wastes coming out of the fish tank than it had to do with grit in the media and the roots of plants and other organic matter that did not come out of the fish tank.  So in that case (like the story of the grow bed that Murray had to re-fresh, he noted that much of the problem probably came from mineral rock dust he added to the bed and my experience with mint and banana clogging grow beds) even with a swirl filter it really would not change things provided you have enough gravel bed for your fish load and you add worms.

 

However, if you want to run much more than 1 fish per cubic foot of grow bed or 25 fish per 500 liters (figuring harvesting fish around 1 lb or 500 grams) of grow bed then the swirl filter might still be worth a though.  Now if you are going to do something like 3 kg or more of fish per 100 liters of grow bed, then definitely add the swirl filter.

[John Malone]

Hello All,

I'm closing in on actually having an AP system built.   I've got a couple of questions:

 

1) Does anyone know where do you get fish-safe pond liner in Phoenix area at a decent price?

2) Do you have a preference for a pump. I'm looking at a Quiet One 3000. ref:http://www.lifegardaquatics.com/products/product.php?id=10

 

All input greatly appreciated.

John

[TCLynx]

For pond liner, best I've normally found (unless you find a pond place locally that is going out of business) is http://www.justliners.com/aboutus.htm

 

How big is your system going to be?  I can't really spec a pump if I don't know how much water you need to pump or how high.  So tell us,

1-how big your fish tank is going to be

2-how high you will be pumping above the surface of the tank the pump will be pumping from (if placed in the fish tank, aprox water level of the fish tank water or if you will have a sump tank, tell us how far from near the pump in the sump tank up to your grow beds or towers or whatever you will have)

3-Will you be pumping constantly or will you be running on a timer, if running on a timer, how many minutes per hour will the pump be running.  (If you are only running the pump 15 minutes per hour you will need a pump 4 times as big as if you were running the pump constantly.)

 

I've never actually used the Quiet One 3000 but I know some one who has and he likes them for his little 100 gallon fish tank system.  I've used the Quiet One 4000 pumps and I think they are great for up to a 300 gallon fish tank system or a smaller system where you need to pump up to towers.  For bigger systems I would probably switch to a Danner Supreme Mag Drive.

[steve]

I just saw pond liners at Lowes and Home depot in Glendale, in the garden/pond area. Reasonable enough under 100. Fish safe yes, I might double check for food grade safe though.

[John Malone]

Interesting!

 

Home Depot has 13'x20' PVC pond liner that claims to be fish and plant safe for $100.

http://www.homedepot.com/h_d1/N-5yc1v/R-202017067/h_d2/ProductDispl...

 

Does anyone know whether this Pond Skins Pond Liner is suitable for AP?

It's a whole bunch cheaper than the EPDM that I was going to order on line which would have cost $225 shipped.  (Shipping is the killer - $70)

 

Thanks,

John

 

[TCLynx]

I don't think most pond liners get a food grade stamp but I'm comfortable with using the EPDM Firestone pond guard liner for my personal systems.  I don't think the stock tanks get a food grade stamp either.

[TCLynx]

what purpose is the liner going to be put to?  If it's fish and plant safe I wouldn't be too worried about it though flexible PVC liner probably has some materials in it (that though they may still get a food grade stamp many people don't want them touching their food.)

 

What I will warn you about is that PVC often gets brittle in the sun and with age that could be worse.  How heavy duty is the liner?  Will you be making gravel beds out of it or just the fish tank or raft beds?  I might trust lighter duty liner to do raft beds or fish tanks where only water will be wearing on it but if making gravel beds, go for the EPDM.

[John Malone]

Hello TC,

Thanks for the advice.   I think I'll go ahead with the Home Depot liner.  Being fish safe and plant safe has got to be a good start.

As far as your questions re the pump, here are my specs.

1) 500 gallon fish tank.    It's dramatically over sized for what I need but I'm trying to have a large thermal bank to try and offset the weather here in Phoenix.  From what I've read the larger the water volume the more stable the system.

2) Pumping height will be between 2 and 3 feet, depending on the height of the water in the fish tank.

3) I intend to be pumping constantly.

 

Other useful information.

Grow bed size : 6'x4'x1' = 360 gallons which will be about 144 gallons of water when full, assuming void space of gravel at 40%.

Initially only one grow bed, but hope to expand to two down the road.

 

Thanks very much for your input.

John