Backyard Aquaponics
A place to discuss aquaponics

We are so excited! We have found a way to get a garden up and running this year without a rototiller! Having been avid gardeners in Pennsylvania, we have missed it since moving to Texas and we happened to get the tip from a friend about aquaponics.

So, we've got lots of questions, but we started building a system anyway, because we just couldn't help ourselves.

We live on two acres and already have a pond. It sustains itself, contains bass, sunnies, and catfish, cattails, and other water reeds. Plenty of water! So, my question is, is there any reason we can't use it? I have read tons of posts on here about fish tanks, but nothing about natural ponds.

If we keep the medium wet all day and let it drain out at night is that sufficient or is it better to have a timer cycle? We are using an old pool filter pump to pump the water out of the pond and into the first grow bed(which is a kiddy pool), and it will have no problem moving as much water as we need. And do you think lava rocks will be a problem, since they will be easier and cheaper to get hold of?

Is there anything you don't grow in these gardens? And do normal growing seasons apply? We live on the gulf coast, and so frost is not a problem, but the heat usually is and people stop gardening in July and August. But if the plants are obviously in plenty of water, do you think the heat would still be a problem? Ok.(deep breath)

If you will be kind enough to try to answer my question, I will take some time to take pictures and I would love you to critique what we are putting together. I cannot wait to have real tomatoes again - I can hardly stand it!

Welcome to the madness.
I will attempt to answer as many q's as I can, however some of your questions relate to opinion and personal choice.

Lava rock is often referred to as scoria. A search on scoria on this forum will show many of us (myself included) use it.
You pond is already a happily balance ecosystem. You can use it of course, but beware you will need to keep the system in balance.
You will add plenty of veggies, and so will need to add nitrates, so will need to feed the fish extra, or increase stocking density.
Because the pond is probably rather pretty, and sorts itself out, I'd probably set up tanks, and repopulate the pond with grown out fish. But that's just cos I don't like fixing things that ain't broke.
I have found that I can't grow blueberries. there's nothing else that has failed for me.
normal seasons apply, sort of. they tend to be extended slightly I have found. Perhaps because of the temp of the water.
If heat is likely to be a problem, you will want to erect some 50% shade cloth to save the plants from burning. Gravel, especially scoria and such gets very hot and reflects the heat onto the plants. Great for my climate when not in the height of summer, but not for yours perhaps.
Despite the plants being in water the heat WILL be a problem, the water simply can't be absorbed fast enough to protect the extremities. You'll have to do some trials to see how much shade you'll need. And you'll want to move the shade to extend your growing season.

Flooding all day may cause "Root rot", draining all night may stress the fish, as they will have no filtration or aeration.
Get a nitrate tester, if the pond is high in nitrates, but supports itself, then yes you may manage to do this.
Be aware also that using a natural pond normally means you've got some fall in the land, this means a larger than normal pump will be required to make the system function.

I think that covers most of your questions... hint: for ppl like me, if you number your questions it makes it easier to respond, so we don't miss anything, and we know for certain which statement like phrases are really questions in disguise

Thanks for the responses. It helps tremendously. My husband was thinking we might need to add fish, too, and I couldn't see the point, but it makes sense now.
I am trying to get some pictures uploaded, but having a little technical difficulty, I will do my best to explain a little. Our system uses an above ground pool filter to pull water out of the pond and up to the first grow bed, then we simply are using gravity and the natural slope of the ground and drain tubes to fill the other grow beds. The last grow bed's drain tube runs into a rain gutter which lays along the ground and into the reeds at the edge of the pond where the water will run back into the pond. I can't really see that stressing the fish out, since the draining water will simply blend with the water at the pond's edge. 1.Maybe I have that wrong?
With this pump, I can pull as much water as I need, but we are having to fine tune with some ball valves between the grow beds the drain and fill times. 2.Or, other ideas? 3. What is a recommended length of time to have the grow beds full of water, then?

And I am glad you mentioned the shade cloth, because we do have some tree cover that can be brought into service to help us out! Great!

Hi JudyTX

I think the main thing is to achieve a balance between the amount of fish and the amount of filtration and plants. That will be the challenge when using your extablished pond. Will the veges get enought goodness? How many extra fish will you need to make sure they do?

On the bed flooding issue, a good standard for a timed system is to run the pump till your beds are full, then let them drain out slowly. 15 minutes on 45 minutes off is the general rule. For a sytem using autosyphons there is a large variation of timing that will work. Mine flood and drain about 4 times an hour.

It seems that your system is pumping up to one bed then draining through several others (cascading). I guess running the pump till they are all full then letting all the water drain through would work. Work out how long that all takes and set a timer to suit.

I see no issue with returning the water back to the pond as you describe. A nice bit of fall and splash would add some oxygen.

Cheers

1. Depending on how stocked the pond is, not having regular reoxygenation and filtration of ammonia, may stress the fish. Water becomes low in oxygen, and high in ammonia and nitrite.

2. Ball valves are grate for regulating flow. there are some warnings though. A. You must leave at least 1 valve fully open, so as to not strain the pump unnecessarily. B. ball valves can occasionally get gummed up with biofilm, and restrict flow. This happens mostly with low flow, high restriction. To fix, open the valve fully then reset it.

3. there are many ways.
A. Continuous flow beds are not generally recommended, but water is continuously moving through a continuously full bed.
B. Flood and drain with a timer
C. Flood and drain with continuous inflow, and a siphon.

We generally recommend an instantaneous fill. ie, once full, start draining immediately. Growbeds prefer to be empty than full.
A a fast drain is also recommended as it pulls oxygen down into the GB to the plant roots, reducing the chance of root rot.


Lastly, The tree above my GB gives me no end of hassle, dropping annoying leaves onto my gravel, but it's not really a big problem.

Main thing to keep in mind is an established pond that already has a good balance may simply not provide enough nutrients to the grow beds to get good growth for the plants.

If you up the stocking and feeding of the pond to get enough nutrients for your grow beds, you are getting a little dangerous with the large pond as if there is a failure, you might have a big crash and a pond full of dead fish. Remember that aquaponics is a balancing act. Now I could be all wrong and perhaps your pond will grow you some veggies in your one grow bed but remember that you already have pond plants using up nutrients. Most people start a little smaller on their AP systems to learn how to balance things before going large. Then again there are people who have turned swimming pools into AP systems so many things are possible.

How large is the pond anyway? Do you have any extra aeration running into it? Any experience using aquarium type test kits? If you do up your stocking and feeding to the pond to make Aquaponics possible using the pond as your fish tank, you will want to read a lot so you are prepared with some backup aeration and perhaps a backup pump in case of failure since we would not want you to suffer a major issue with ammonia, nitrite, or algae bloom in your pond as they can all cause fish kills.

Great to have you aboard JudyTX. Welcome to the world of AP! I understand missing the gardens of PA. I was originally from Ohio with an acre of garden and could not get anything to grow here in Florida. I have found that growing veggies in the AP system has been far more satisfying than I ever had before. Enjoy.

+1 for TC's post.

I'd do a separate AP system, and populate your pond with AP fish when they're big for aesthetics and sport fishing.

I think having a large volume of water relative to fish load is great: it takes some time to build up nutrients enough to really make things flourish, but the fish benefit from 1) less fluctuation in temperature, 2) less fluctuation in water chemistry, and 3) less likely to transmit disease and parasites through crowding. (I would guess that a natural pond has some unwanted minor problem organisms that could become major problems with crowding).

One major issue is that when nutrients go up, so does pond plant growth, including water plants (no problem, but it does remove nutrients you might want for your garden) and single-cell algae (that, in excess, can lead to chemistry fluctuation or even ecosystem collapse). Most folks either have plants that remove nutes to low levels or shade the water or have fish that eat the algae (like tilapia....are they legal in TX?).