I have decided on using bluegill in my AP setup, I've got a few questions.

[DALE MORRIS]

I have a 16X24  with 5 -275 gal IBC's painted black for passive solar heat.  I plan to put in an AP setup using bluegill.  First question is how many can I raise in 1 275 gal tank? #2 I have a large 4 acre spring fed pond well stocked with bass, bluegill & crappie, can I utilize my pond inwith my AP operation?  #3  How do you determine how many fish to grow in each tank, and how many growbeds a tank will support?  Do you continually add baby fish to have different stages of fish in the tank at the same time?#4 How big should the bluegill be at harvest? We like to fillet them so is 1 lb about right?

 

Thanks

[Ron Thompson]

Just a thought (and I just got up, so it may not be a coherent thought)..  Is there some reason you could not draw water directly from the lake and then let it flow back to the lake?

For fish stocking, just put a pen along the shoreline or a dock in the lake that you could draw from.

 

Main issue I see is if the lake water is rich enough in nutrients. I'm betting it would be similar to a low density population system. Those work quite well.

 

[TCLynx]

First, don't base your stocking on the fish tank size so much as you should base your stocking on the filtration and aeration available.  If you only have say 100 gallons of grow bed for each IBC, I would start with only stocking about 10-15 fish per IBC and then only up the number once you have gained enough experience to know how many fish you can stock.

 

I have systems with twice as much gravel bed volume as fish tank and am not running huge amounts of fish to support them.  If you keep the solids for mineralization in the system, you don't need all that many fish compared to the UVI raft bed model of aquaponics.  Are you planning gravel beds or raft beds?

 

I also do not have a steady addition of new fish while I remove large fish, the numbers in my system fluctuate quite a bit but the solids slowly breaking down in the gravel beds tend to help keep the nutrient levels more stable.

Three fish to a pound is not an uncommon size for harvest of bluegill, insisting that they grow out to 1 lb might put you in the camp of opinion that bluegill are too slow for aquaponics

 

Ok now back to the pond.  You may well be able to utilize the pond however, balancing such a thing may be a real challenge.  Most people who have tried to turn a large swimming pool to aquaponics have run into issues since few are likely to use enough grow beds to stock the pool to the max but without enough grow beds the nutrient balance and keeping algae from growing in the pool can be a real challenge as well as how to filter all that water every hour.  So the standard formula of how to run and stock a media based aquaponics system kinda fall short when trying to do a natural pool or use pond water so then the question is going to be, What are your goals and desires for the aquaponics system?

Are you wanting to grow lots of fish?  Are you wanting to grow lots of veggies?  Which is priority?  How much money do you want to put into aerating the pond to be able to grow more fish?  There are many things you could probably do however I don't think there is much formulated about pond aquaponics so I doubt you will get any hard tested answers here, only some ideas that haven't been tested out.  If the pond is that productive, you could simply catch lots of bluegill out of it for eating and perhaps use some of the pond water for irrigating gardens around the pond.

[DALE MORRIS]

Thanks for the input.  I was just wondering if the pond could be of use,ie starting up the system, ect.  I was not planning on using it inastead of traditional AP systems.  My greenhouse already has 5 IBC's in it for paassive solar heat and I want to use them if possible for fish tanks.  My primary objective would be to grow as many veges year round as I can, and the fish would be a welcome additin, I am trying to be as self sufficent as possible in every way  You never know.........

 

 

dale

[DALE MORRIS]

Thanks, Ron the pond is a 4 acre very clean spring fed pond with lots of bluegill, bass, crappie & catfish and a few grass carp.  I was just wondering if I could supplement a traditional AP system in my greenhouse with the stuff I already have.

 

 

Thanks,

 

DaleRon Thompson said:

Just a thought (and I just got up, so it may not be a coherent thought)..  Is there some reason you could not draw water directly from the lake and then let it flow back to the lake?

For fish stocking, just put a pen along the shoreline or a dock in the lake that you could draw from.

 

Main issue I see is if the lake water is rich enough in nutrients. I'm betting it would be similar to a low density population system. Those work quite well.

 

[TCLynx]

I've known of people using fish from an on site pond to stock their AP systems.  Challenges might include possible parasites or diseases but when you bring in new fish that is almost always a risk so being able to isolate a section of a system with new fish for quarantine is often a good idea so if you have to salt or something you are not affecting the entire system.

 

You might also run into issues with feed training with some types of fish but bluegill are pretty notorious for being easy to feed so you will probably be ok there.

 

Using pond water to start up your system might be good if you are using fish from the pond to stock the system since they will already be used to that water so it can reduce shock from the move.  However, the pond water will probably not contain as much to help cycling up the aquaponic system as many people believe and even if you were to use sterile water to start the system, it will still cycle and the amount of time it takes will probably only differ minimally.  The bacteria that colonize an aquaponics system to provide the bio-filteration are pretty much everywhere that is not completely and regularly sterilized and will colonize given the proper conditions and and food source.  They are basically the same bacteria that work in good soil or any aquarium filter.

 

So, read up on the nitrogen cycle (fishless cycling is a good thing) and do some reading on pH and water chemistry to help you choose appropriate media and be prepared with the test kit and other materials you will need as the system matures.  If you feed the fish high quality feed, you can get a lot of plants out of a relatively minimal fish load.  People are often amazed at how much veggie beds can be supported on a relatively small amount of fish.  (Those IBC systems with just the top cut off and acting as the grow bed for the rest of the IBC as a fish tank are really not providing enough grow bed to stock the fish tank much at all.)  You could probably use one IBC as fish tank and then fill the greenhouse with grow beds and have a sump tank and leave the rest of the IBC's as your heat sinks/thermal mass/grow bed stands and be just fine.

[DALE MORRIS]

TC, Thank you for that extremely good info.  You are very helpful and much appreciated.  That souunds like a great idea with using one tank for fish and leaving the others alone.  I didn't know if one tank would provide enough nutrients for my greenhouse full of plants.  How can I moniter the nutrient level to make sure that one tank of fish will be suffienct.  I want to get started Now, so I guesss I should start with building my growing beds.  What do you suggest as tyhe best way to build my growing beds?  I am including a picture of the inside of my greenhouse. Please excuse the mess, as it hasn't been used since May when it started getting too hot to grow in.  I have 70% shade cloth to cover the entire greenhouse and ventelation fans, but there was no need to use them before as I have a big garden using raised bed weed free, drt free, intensive gardening methods, as well as a large conventinal dirt garden. Also when i just went to the greenhouse to take these pictures I was wondering if I could convert my growing tables to AP growing beds with some beefing up for the weight?  If so would you reccomend clay pellets for the medium as opposed to gravel, or a combination of both?

TCLynx said:

I've known of people using fish from an on site pond to stock their AP systems.  Challenges might include possible parasites or diseases but when you bring in new fish that is almost always a risk so being able to isolate a section of a system with new fish for quarantine is often a good idea so if you have to salt or something you are not affecting the entire system.

 

You might also run into issues with feed training with some types of fish but bluegill are pretty notorious for being easy to feed so you will probably be ok there.

 

Using pond water to start up your system might be good if you are using fish from the pond to stock the system since they will already be used to that water so it can reduce shock from the move.  However, the pond water will probably not contain as much to help cycling up the aquaponic system as many people believe and even if you were to use sterile water to start the system, it will still cycle and the amount of time it takes will probably only differ minimally.  The bacteria that colonize an aquaponics system to provide the bio-filteration are pretty much everywhere that is not completely and regularly sterilized and will colonize given the proper conditions and and food source.  They are basically the same bacteria that work in good soil or any aquarium filter.

 

So, read up on the nitrogen cycle (fishless cycling is a good thing) and do some reading on pH and water chemistry to help you choose appropriate media and be prepared with the test kit and other materials you will need as the system matures.  If you feed the fish high quality feed, you can get a lot of plants out of a relatively minimal fish load.  People are often amazed at how much veggie beds can be supported on a relatively small amount of fish.  (Those IBC systems with just the top cut off and acting as the grow bed for the rest of the IBC as a fish tank are really not providing enough grow bed to stock the fish tank much at all.)  You could probably use one IBC as fish tank and then fill the greenhouse with grow beds and have a sump tank and leave the rest of the IBC's as your heat sinks/thermal mass/grow bed stands and be just fine.

[TCLynx]

I expect you could convert your existing benches for aquaponics.  I'm not sure of the best way of going about reinforcing them but I expect it would be doable.  As to building the beds.  I've done lumber and pond liner beds in the past but being here in Florida with excessive termites, I don't do that anymore.  But if you can come up with a way to build them while protecting the liner from contact with wood or other materials that termites find comfortable you would probably be ok.

You might also be able to set up say one bench as media beds and if you find you have enough nutrients left and if the filtration is enough then you might be able to set up the second bench as a raft or NFT or seed starting or fodder bench.

 

How big are the benches?

 

I'm kinda cheap so I use gravel as my media.  The clay balls will be lighter but since they are manufactured and have to come from far away most of the time, you are going to pay for the shipping one way of another.  For me to get just one pallet full of manufactured media just the freight generally costs as much as the full price on gravel and delivery for a 6 ton dump truck load.  So you will have to make decisions about what is important to you.  Find some place locally that supplies gravel and go get some samples and bring them home to run some pH tests to see what will be the right size and not affect your pH.  You need to avoid limestone and marble but lava rock, granite and quartz type river rock is often acceptable.  There is also expanded shale that might be an option but again the whole shipping/manufacture thing plays a part if you are not near where it is minded and manufactured.

 

As for monitoring nutrient levels.  You will need a freshwater master test kit and with that you will not only be able to monitor the toxic ammonia and nitrite as well as pH but you will also be able to track your nitrate levels which are the indicator of nutrients for the plants.  Though there are systems out there that are so perfectly balanced that they never actually see nitrate readings but the plants all grow well and happy.

[DALE MORRIS]

Thank you again for your valuable time to advise me.  My tables are now 35" wide by 16 ft.  I want to raise as many vegetables and fish year round in the space I have.  I can build the growing beds myself if pointed in the right direction. How will I be able to know ahead of time if one fish tank wil supply enough nutrients for both growing beds?  I guess I could go ahead and build both and if one tank was not enough then I could put fish in a 2nd tank.  It has benn hotter than blazes here over 100 deg. I don't have my shade cloth on the greenhouse and my water temp is 95, but if I had shade cloth on the greenhouse and had the vent fans on I'm sure I could bring the temp down.  We are in the extreme southern tip of Ill in zone 6B.  right next to KY, TN border so it doesn't get really cold here.  I think I can keep the temp up enough in the winter for the bluegill.  They do just fine in my pond.

Can you recommend a brand & source for the pond liners and the master test kit? Do my growing beds need to be 12" thick?  Thanks,

 

Dale

 

 

I expect you could convert your existing benches for aquaponics.  I'm not sure of the best way of going about reinforcing them but I expect it would be doable.  As to building the beds.  I've done lumber and pond liner beds in the past but being here in Florida with excessive termites, I don't do that anymore.  But if you can come up with a way to build them while protecting the liner from contact with wood or other materials that termites find comfortable you would probably be ok.

You might also be able to set up say one bench as media beds and if you find you have enough nutrients left and if the filtration is enough then you might be able to set up the second bench as a raft or NFT or seed starting or fodder bench.

 

How big are the benches?

 

I'm kinda cheap so I use gravel as my media.  The clay balls will be lighter but since they are manufactured and have to come from far away most of the time, you are going to pay for the shipping one way of another.  For me to get just one pallet full of manufactured media just the freight generally costs as much as the full price on gravel and delivery for a 6 ton dump truck load.  So you will have to make decisions about what is important to you.  Find some place locally that supplies gravel and go get some samples and bring them home to run some pH tests to see what will be the right size and not affect your pH.  You need to avoid limestone and marble but lava rock, granite and quartz type river rock is often acceptable.  There is also expanded shale that might be an option but again the whole shipping/manufacture thing plays a part if you are not near where it is minded and manufactured.

 

As for monitoring nutrient levels.  You will need a freshwater master test kit and with that you will not only be able to monitor the toxic ammonia and nitrite as well as pH but you will also be able to track your nitrate levels which are the indicator of nutrients for the plants.  Though there are systems out there that are so perfectly balanced that they never actually see nitrate readings but the plants all grow well and happy.

[TCLynx]

Well I would recommend getting started with an eye out to expand later.  Like get one of the tables online with beds and one fish tank going so you can cycle the system up (highly recommend fishless cycling.)  Then as things go you can add on later as you figure out what you want to do different.  Also, aquaponics does require some patience and it improves with age (kinda like organic soil building but for aquaponics it is bio-filter building.)

 

How to know if one tank will be enough, well it is hard to know for sure since it will depend on the type of plants you grow and the feed you use and the temperatures.  But if one of those tables were turned into a 12 inch deep bed it will hold around 300 gallons I expect and a single IBC fish tank if fed well could probably handle growing 600 gallons worth of veggie beds.  You would just need to have a sump tank to handle the water level fluctuations or perhaps you would want to make it into 4-6 beds and feed them by indexing valve so you only flood one at a time.  I do think having grow beds at least 12 inches deep is a good thing.  I run beds as deep as 24 inches and I know someone who is using full depth IBCs as his grow beds.

 

Aquaponics is all about balance and you may find that you don't have enough nutrients to plant really heavily through winter when the water is cool and the fish are not eating as much but come summer when the fish are feeding well you may find that you can expand out of the greenhouse with perhaps a raft bed or NFT pipes or something to use up excess nutrients and grow more plants when the weather is good for outdoor growing.

 

Here is a discussion that will probably answer your question about test kits

 

For pond liners, I like EPDM for liner durable enough for use with gravel search for just liners plus, they come in 5 or 5.5 foot wide rolls.  If you want food grade liner there is something called durascrim and the only place I know to get it is from the ladies at green acres organics

 

[Ron Thompson]

I just used a Firestone 45 mil pondliner and was very impressed by it's construction. If the liner is coming in contact with the ground, I strongly suggest using a underliner mat. It is very inexpensive and will protect against puncture.

 

I found the following site to be quite informative as well: http://www.westernliner.com/pond-liners.html

 

as for a retailer - I shopped around and eventually settled on pondliners.com. However if you need a large amount, there were several places which sold by the foot. Just search the net with patience.

[DALE MORRIS]

Thanks TC Where is the best place to buy thr master test kit?  Also in my raised bed garden I use concrete blocks for my beds, would that be a good thing to use for the gravel beds with a pond liner, say 2 blocks high and 16' long?  How many lbs. of bluegill could you expect to harvest out of one tank in a season?

TCLynx said:

Well I would recommend getting started with an eye out to expand later.  Like get one of the tables online with beds and one fish tank going so you can cycle the system up (highly recommend fishless cycling.)  Then as things go you can add on later as you figure out what you want to do different.  Also, aquaponics does require some patience and it improves with age (kinda like organic soil building but for aquaponics it is bio-filter building.)

 

How to know if one tank will be enough, well it is hard to know for sure since it will depend on the type of plants you grow and the feed you use and the temperatures.  But if one of those tables were turned into a 12 inch deep bed it will hold around 300 gallons I expect and a single IBC fish tank if fed well could probably handle growing 600 gallons worth of veggie beds.  You would just need to have a sump tank to handle the water level fluctuations or perhaps you would want to make it into 4-6 beds and feed them by indexing valve so you only flood one at a time.  I do think having grow beds at least 12 inches deep is a good thing.  I run beds as deep as 24 inches and I know someone who is using full depth IBCs as his grow beds.

 

Aquaponics is all about balance and you may find that you don't have enough nutrients to plant really heavily through winter when the water is cool and the fish are not eating as much but come summer when the fish are feeding well you may find that you can expand out of the greenhouse with perhaps a raft bed or NFT pipes or something to use up excess nutrients and grow more plants when the weather is good for outdoor growing.

 

Here is a discussion that will probably answer your question about test kits

 

For pond liners, I like EPDM for liner durable enough for use with gravel search for just liners plus, they come in 5 or 5.5 foot wide rolls.  If you want food grade liner there is something called durascrim and the only place I know to get it is from the ladies at green acres organics

 

[TCLynx]

I'm not sure if concrete blocks stacked would be able to hold gravel back from pushing the blocks out.  It may work for raft beds where it is only water pushing out but gravel with flood and drain water and plant roots can put much more force outward so you might need to pound stakes down to help hold the blocks in from toppling outward.

 

The test kits, well you can get them from Sylvia by clicking on the shop tab at the top of the page.  Or you might search the internet for deals on them.  That pet place/that fish place sometimes has a good price on them when they have a sale.