Rob's System - Homework (At This Stage)

[Rob]

Hi Everyone,

I've been reading here for a while, and researching all that i can find on Aquaponics, and i'm very excited to give it a try.

As mentioned in my "introduction", i'm an avid home farmer growing lots of fruit and veggies from my suburban home. Currently i have about 100 square metres of productive garden, and it's going well

Anyway, so i have a few queries that i thought i would post here as you all seem very knowledgeable. I appreciate any info you can offer.

1. I was considering digging a pond into the ground, rather than finding a suitable size "tank". My reason for this was to not only make it productive, but a decorative installation also (i already have a small pond, but too small to use for this). Is this ok? Tanks seem to be more popular...
2. If a pond is ok, how thick does the liner need to be for a ~2000L pond? I've heard about some fish that can potentially cause issues with the liner like suckerfish - is this something to consider?
3. I love the idea of the deep flow systems for lettuce etc - is this ok to try for a beginner?
4. I would like to grow deep root crops like tomato, corn, and other veggies that i grow in the soil already, so understand that they would require media beds with the flood/drain method. Can you run both media and deep flow beds from the one tank/pond? I understand they would need different pumps etc.
5. I notice many people grow in a greenhouse. I don't really have this option - will this cause issues?
6. If i don't use a greenhouse, do i need to stop rainwater getting into the system with covers of some sort, or is it ok?
7. Does the tank/pond need to be covered to prevent algae buildup, or will it be taken care of by the fish?

I apologise for the numerous questions, and indeed if they are very "newby" questions, but i like to think everything through before i get going

Thanks very much!

Rob

[Rob]

And sorry, a few more q's.

1. Any recommendations for Fish suitable around Sydney?
2. When you are in between Fish crops (or yet to introduce them), you can just feed your plants with Seasol & urea is that correct?

I want to start big (as i always do), but am unsure if it's just asking for trouble if i do so

Thanks

Rob

[Ravnis]

1. yes, there are members that make a pond work.
2. My sump in fact is a very small pond lined with pond liner I bought at a home depot. Don't remember for sure the exact thickness, but I think it was 10-12 mil. It holds around 300 gallons. If I was to build it again I would put old carpet or shadecloth on top of it to protect the liner.

4. Yes, you would need to consider continous flow so that you don't empty the pond. With continous flow you would not require separate pumps.
5. The greenhouse protects plants from frost damage as well as helps with heating the fish water. Whether you need one depends on how cold it gets and plant and fish selection. I plan to run 2 systems when I get the second one built. One in a greenhouse for overwintering and another for use just through april to october (my spring, summer and fall).
6. I uncovered my greenhouse for several months during the summer and fall and the rain did not cause major issues. The main issue with rain in a pond is thermal inversion where water with low oxygen content hits the water and forms a suffocation layer if the water is not aerated or mixed constantly.
7. Some fish will eat algea, there are also things like barley straw that can be added to control algae. As your plants take root they will "starve" the algae to an extent, but not get rid of it completely.

Hope this helps.

There is a thread here with a really nice setup for a decorative pond complete with an upside down aquarium. I was rather envious of this setup and it really shows some fine craftsmanship.

[GaryD]

Hi Rob,

For another perspective on your questions:

I was considering digging a pond into the ground, rather than finding a suitable size "tank". My reason for this was to not only make it productive, but a decorative installation also (i already have a small pond, but too small to use for this). Is this ok? Tanks seem to be more popular...

Tanks are more popular for two reasons......they are less work to set up and they enable greater control of the production parameters associated with fish production.

I prefer tanks for the latter reason.

2. If a pond is ok, how thick does the liner need to be for a ~2000L pond? I've heard about some fish that can potentially cause issues with the liner like suckerfish - is this something to consider?

If you decide to go the pond route, I'd offer the following advice:

• Make your pond a turkey nest pond.....above the surrounding area....to stop rainwater water from flooding into your pond. It may have picked up toxins from where your neighbours or the local shire council have been spraying weeds.
  
• Buy an LDPE (low density polyethylene) liner of about 20 mil (thousands of an inch) thickness. Line the pond with old carpet or similar before you lay the liner.

3. I love the idea of the deep flow systems for lettuce etc - is this ok to try for a beginner?

Raft systems are probably better suited to tanks because you can more effectively control water quality.

You might like to think about taking your pond water for use on your existing soil-based gardens.....or wicking beds.

4. I would like to grow deep root crops like tomato, corn, and other veggies that i grow in the soil already, so understand that they would require media beds with the flood/drain method. Can you run both media and deep flow beds from the one tank/pond? I understand they would need different pumps etc.

If you opt for aquaponic growing systems for your pond, you can run both types of growing system.....but, as Ravnis has suggested, you might be better to go for continuous flow (rather than flood and drain). You don't need two pumps.

5. I notice many people grow in a greenhouse. I don't really have this option - will this cause issues?

A greenhouse is not necessary in your part of the world....but it will extend your growing season for both fish and plants.

6. If i don't use a greenhouse, do i need to stop rainwater getting into the system with covers of some sort, or is it ok?

You can use rainwater to top your pond up (it's the best option) but don't allow uncontrolled rainwater access to your pond for the reason mentioned above.

7. Does the tank/pond need to be covered to prevent algae buildup, or will it be taken care of by the fish?

Most of the species that you'd be likely to keep in your area would not eat much in the way of algae (although they may eat the other organisms that feed on algae).

Algae will be an issue. It can be controlled by covering the pond or by using the barley straw Ravis referrred to.

A very good pond-based system is that run by KenR60.

Silver Perch would be a good fish for you to begin with. Other options include eel-tailed catfish or even gold-fish (they're hardy and well-suited to pond culture).

2. When you are in between Fish crops (or yet to introduce them), you can just feed your plants with Seasol & urea is that correct?

I wouldn't recommend the use of urea with any system that has fish in it. It's too easy to overdo it and kill the fish. Modest application of Seasol is probably the better way to go in that situation.


Gary

[GaryD]

Hi Rob,

I was thinking a bit more about this pond thing.

• Ponds pose more of a safety risk for toddlers. It’s harder for a child to climb into a tank than it is a pond and a tank is easier to cover to exclude unwanted access.
• There is a greater likelihood of toxic contamination of a pond particularly through run-off.
• It will be harder to harvest fish from a pond or to catch them for an other reason - particularly if the pond is irregularly shaped.
• Control of water temperature will be more difficult.

On the positive side, ponds can more readily exploit gravity when it comes to draining water from growing systems back into the fish pond.

Hope this helps.


Gary

[Rob]

Hi Rob,

I was thinking a bit more about this pond thing.

• Ponds pose more of a safety risk for toddlers. It’s harder for a child to climb into a tank than it is a pond and a tank is easier to cover to exclude unwanted access.
• There is a greater likelihood of toxic contamination of a pond particularly through run-off.
• It will be harder to harvest fish from a pond or to catch them for an other reason - particularly if the pond is irregularly shaped.
• Control of water temperature will be more difficult.

On the positive side, ponds can more readily exploit gravity when it comes to draining water from growing systems back into the fish pond.

Hope this helps.


Gary

Thanks Gary for all your info.

I'm still struggling to wrap my head around why a pond is harder to keep in shape than a tank?
Can you give me a few reasons why temperature control and water quality etc is more difficult to manage?

I don't have kids, so no problems there ;-)

I'm not determined to have a pond instead, just trying to get all the facts
I guess my thinking is mainly that it's just easier to build a large pond thank get a large tank of some sort much like what Outbackozzie has done.

Thanks,

Rob

[Rob]

1. yes, there are members that make a pond work.
2. My sump in fact is a very small pond lined with pond liner I bought at a home depot. Don't remember for sure the exact thickness, but I think it was 10-12 mil. It holds around 300 gallons. If I was to build it again I would put old carpet or shadecloth on top of it to protect the liner.

4. Yes, you would need to consider continous flow so that you don't empty the pond. With continous flow you would not require separate pumps.
5. The greenhouse protects plants from frost damage as well as helps with heating the fish water. Whether you need one depends on how cold it gets and plant and fish selection. I plan to run 2 systems when I get the second one built. One in a greenhouse for overwintering and another for use just through april to october (my spring, summer and fall).
6. I uncovered my greenhouse for several months during the summer and fall and the rain did not cause major issues. The main issue with rain in a pond is thermal inversion where water with low oxygen content hits the water and forms a suffocation layer if the water is not aerated or mixed constantly.
7. Some fish will eat algea, there are also things like barley straw that can be added to control algae. As your plants take root they will "starve" the algae to an extent, but not get rid of it completely.

Hope this helps.

There is a thread here with a really nice setup for a decorative pond complete with an upside down aquarium. I was rather envious of this setup and it really shows some fine craftsmanship.

Thanks for the information Ravnis.

We don't get frosts or much cold here... something makeshift for the coldest month of winter may be required, but it would only get down to the 5-10°C range at worst.

A greenhouse through summer here would actually kill everything - since we get to 40°C some days - i have a little one for seedlings that i use in Winter, but nothing would survive in it during summer

Thanks for the info about the Barley Straw - i'll definately have to check it out!

THanks again mate.

Rob

[Dufflight]

I have a inground pool and find the temp to be very stable. A pond like OBO's makes a great fish tank. And later you can form it up and make it a concrete one.

[Rob]

I have a inground pool and find the temp to be very stable. A pond like OBO's makes a great fish tank. And later you can form it up and make it a concrete one.

Thanks Dufflight.

Yeah i would think that a pond option would be more temperature stable.

OBO's stuff rocks

I think having it as a decorative option AS WELL (function first, but making it look great too ie surrounding with river stones etc etc) is just awesome. Then if it takes up a chunk of the back yard, then it's not taking away from the leisure aspect of the yard too.

Rob