You are probably going to get a similar answer from keith because we tend to share the same philosophies.
Warning, aquaponics is addicting. You will start with a 300 gallon system and once it's built you will think of a half dozen things you can do to improve it... expand it... and once you apply your improvements/expansion, rinse repeat.
Like most things "it depends". Rainman pretty much has the consensus down which is kind of the base line i would recommend to anyone for their first go. The one lb of fish per 1 square foot of media (~7.5gallons) rule of thumb is also a little bit subjective because what media are you using? One cubic foot of 3" river rock has a lot less surface area for bacteria than the same volume of pea gravel. Once your system is mature you can start to increase your fish load to see when water quality starts to suffer. (if highest fish load is your goal)
Your link doesnt seem to work because of some weird characters, but I have tinkered with that Wilson Lennard's spreadsheet and it seems to be based off of the UVI research and more accurate than any rule of thumb i know. At a glance there is something wrong with your calculations because fruiting plants take way more nutrients than leafy plants and there's now way you can grow more tomatoes per lb of fish than cabbage. Not without additives anyway. Remember that Aquaponics is nitrate rich (vegetative/green nutrients) and a lot less on the Potassium and Phosphorous department (flowering/fruiting nutrients) which tomatoes will require a lot of.
I dont use additional filtration or settling tanks in my systems so I try to keep a modest fish load. I allow for the solids to break down in my grow beds (with help from red wiggler worms) which adds micro-nutrients to the system through mineralization. The only additive i use is a tablespoon of cheleated iron every few months. Sometimes i bury chicken eggs shells in the grow beds to recycle the calcium but i dont believe i "need" to. I get calcium and magnesium in my tap water.
Personally, I dont start all of my fish at the same time. Right now i have 4 fish tanks all running in one system. I am mindful to keep fish of the same size in each tank but i can stagger production and harvest times.
There's no need to worry about reproduction in a 300 gallon tank. unless you "rescue" the eggs or the fry they will not be able to escape predation. .
Rainman, I read a lot of badflash's information and other sources I dont remember what tilapia information i have taken from his threads but the mention was only for credit the egg tumbler idea because that is where i got the idea to build mine. Any information in the thread is based on information from multiple sources cross referenced with my limited but very successful experience with raising tilapia.
I agree, that if the mother is allowed to brood the fry to full term, I typically gain more fry. However, this means moving all of the other fish out of the breeding tank because fry do not live very long in a 55 gallon tank with a full grown male and 4 females. I think getting less eggs early has most to do with the mother swallowing eggs in her panic while being handled. Of the eggs that make it to the tumbler, I have good hatch rates... Above 90%. Personally, i only try to save a couple dozen fry each year so if i get part of one brood i am set.
Yesterday, 6/11/2013, I was moving a couple of tilapia from my main tank to the HSB tank for algae control and accidentally caught a brooding mother in my net. I wasnt expecting the brood so i had the wrong net and no nursery tank prepared. Still I was able to collect about 50 "sac" fry and my tilapia breeding for this year is now complete!
A follow up note. The eggs also seem to be stronger than the swimming fry. I have killed a few hundred fry because the mom was spitting the fry out in the net and then crushed them with her flopping around. The eggs dont seem to crush as easily.
I owe you guys pictures of my "current" system. These are pictures from october 2012 of the START of a very big system but I have decided to go a different route. Once i get my first ferrocement tank and grow beds built these IBC's will be relocated to the garage for breeding tanks/wintering system. I think ibc's are an eyesore and i think i can make the system much more aesthetically pleasing with ferrocement.
IBC's on cinder blocks, I am sure there is a white trash joke in here somewhere. The three "higher" ibc's overflow into the grow beds which drain to the two lower ibc's
Wood grow beds with pond liner. It's tough to see but the 2 IBC;'s on the ground are connected via 2" pvc. I am only using one pump.
Expanded shale media, A 4" media guard around the bell siphon that i have not yet gotten to work exactly right. I am just using a stem pipe and the grow beds are constantly flooded.
I'll try to take some current pictures later today and show some of the plant growth. Or a video may work better?
sorry about all the pauses i wasnt really prepared, just walking around and talking. I made some mistakes.
clarifications: 1) I keep saying poor water quality but i just mean poor visibility. The water quality is fine. 2) I keep referring to algae in the tank and while there is some algae it was mostly moss. 2) I mention the "small" ibcs and the "big" ibcs.. They are the same size. The "big" ones are just raised up. 3) i dont think my system is overstocked, but i do think it could feed plants in 6 to 8 grow beds. Once the fish are fully grown i would probably have a capacity issue.
Something i didnt mention but meant to. The water temp was 92 degrees yesterday which was roughly ambient temperature. Past systems were shaded and even during two month long 100-110 degree heat waves it never made it to the high 90's. So i am working on shading the ibc's with shade cloth to see if i can bring the water temps down.
You are probably going to get a similar answer from keith because we tend to share the same philosophies.
Warning, aquaponics is addicting. You will start with a 300 gallon system and once it's built you will think of a half dozen things you can do to improve it... expand it... and once you apply your improvements/expansion, rinse repeat.
Like most things "it depends". Rainman pretty much has the consensus down which is kind of the base line i would recommend to anyone for their first go. The one lb of fish per 1 square foot of media (~7.5gallons) rule of thumb is also a little bit subjective because what media are you using? One cubic foot of 3" river rock has a lot less surface area for bacteria than the same volume of pea gravel. Once your system is mature you can start to increase your fish load to see when water quality starts to suffer. (if highest fish load is your goal)
Your link doesnt seem to work because of some weird characters, but I have tinkered with that Wilson Lennard's spreadsheet and it seems to be based off of the UVI research and more accurate than any rule of thumb i know. At a glance there is something wrong with your calculations because fruiting plants take way more nutrients than leafy plants and there's now way you can grow more tomatoes per lb of fish than cabbage. Not without additives anyway. Remember that Aquaponics is nitrate rich (vegetative/green nutrients) and a lot less on the Potassium and Phosphorous department (flowering/fruiting nutrients) which tomatoes will require a lot of.
I dont use additional filtration or settling tanks in my systems so I try to keep a modest fish load. I allow for the solids to break down in my grow beds (with help from red wiggler worms) which adds micro-nutrients to the system through mineralization. The only additive i use is a tablespoon of cheleated iron every few months. Sometimes i bury chicken eggs shells in the grow beds to recycle the calcium but i dont believe i "need" to. I get calcium and magnesium in my tap water.
Brian,
Thanks.
What do you consider a modest fish load? I'll be eventually going up to about .50 lbs. of fish per gallon as I do some serious mechanical filtration along with 4 cubic feed of mb3 media for biofiltration after mechanical filtration in an mbbr filter, which has enough surface area for about 200 lbs. of fish.
Could the tomato calculations seem off due to Glynn's heavy fish load of 0.50 lb.s of fish per gallon of water? Glynn also does not do any water changes and he uses redclaws to clean things up somewhat in the raft tanks. His redclaws actually take residence in the roots of his plants.
Last edited by Cecil Baird1; 06/12/1310:59 AM.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
I consider a modest fish load to be roughly less than or equal to 1 lb of fish per 6 gallons of *media*. The problem is. When i am running so many different species and ages it's difficult to really know my fish load at any given time. Maybe i can develop some ways to track my fish and vegetables better once my main projects are complete.
With your mechanical filtration do you have to backwash and discharge water to clean the filters?
I hesitate to speak on raft type systems because I dont practice that technique. It's a very viable technique and is generally considered the best practice for commercial scale aquaponics. It's also what UVI did all of it's scientific research on so it's more mature than my media based grow beds as far as technology. I do know that many commercial scale aquaponics companies try to raise only the minimum amount of fish required to grow the plants. The general idea is to try to break even on the fish and profit on the produce sales. Obviously i have no idea how viable that is as a practice, but rafts dont supply a lot of surface area.
I would like to work with redclaws but i havent the space set aside or the supplier. My marble crays eat plants and are prolific eaters of roots so i would never use them in a raft system.
Far be-it for me to say someone cannot do something, but i dont see how someone could grow more tomatoes than salad given the same inputs. It's a zero sum game.
If i net her she will spit out or swallow all of her eggs. I have had people report if you dump all the eggs into the same isolation tank with her she will pick them back up once she calms down but that has not been the case the few times i tried it that way. Your results may vary.
With your mechanical filtration do you have to backwash and discharge water to clean the filters?
Brian,
Thanks for the info.
I don't backwash. My filter (clarifier) consists of 55 gallon drum packed with deer fence netting cut into sections and two filter pads on top of that. Water comes into the bottom of this via u-tube 2 inch PVC siphon. A small mag drive pump sits on top of this and pulls the water up through the filter material. The pump then directs the clarified water to another 55 gallon drum which is my biofilter (moving bed bioreactor (mbbr) or a rotating biocontact filter (rbc) in a tank, both homemade.
Cleaning the clarifier is relatively easy. I pull off a pvc extension and temporarily cap the siphon in the clarifier tank. I then open a valve on a hose connected to the bottom of the clarifier tank. The water in the clarifier tank drains out and goes to a raised garden. Once it's drained I pull the pads and filter material out and spray them off with a garden hose, holding them in the tank to allow the debris to stay in the tank and place the cleaned material temporarily into a clean garbage can. Then scour the bottom of the now empty tank and drain.
Next the clarifier tank is filled with fresh water and once the water level rises to the end of the siphon tube, the u-tube siphon is uncapped and and the extension is fitted back on. Filter material is packed back into the tank and pump placed back on top, and it's ready to go. It sounds like a lot of work but it isn't. I've been told this simple filter removes particles down to 60 microns.
This accomplishes removal of suspended solids and a water change at the same time. A totally external stand pipe connects to the center drain. It's kept empty until a gate valve is pulled, whic causes water to violently gets pulled into it and up is my settleable solids filter. It pulls any debris around and in the center drain in the circular fish tank. That water and solids is also directed to the raised garden. Only uses about 2 gallons per purge and I usually do that twice a day.
The clarifier filter works so well it will filter out fine precipitated iron from well water (when I first fill the system) to make the water gin clear. In fact, I use the same principal to make my own separate iron filter, with two drums side by side if I have fry and need to remove the iron in a strictly RAS system. Of course I will welcome the iron in the aquaonics system.
Last edited by Cecil Baird1; 06/15/1306:29 AM.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
BTW I've decided to plant 20 lbs. of mostly male 3 to 5 inch tilapia in the system, which at about 100 gms/meter of surface area of feed per day, at 1.75 % of fish mass feeding rate means I can plant about 1/2 of my DWC tank for now. I figure it won't take long for them to double in size and I'll be able to plant the entire surface area of about 3 square meters. I can also easily add more surface area if need be.
Unfortunately picking up the fish yesterday did not work out due to some issues with my hauling tank system.
Last edited by Cecil Baird1; 06/15/1306:16 AM.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
Brian, You mentioned of something to the fact that the tilapia were 1.25-1.75#. What was the period of time it took for that, one summer?
Also, you mentioned shipping and buying tilapia once every 4-5 years. Why is that? Is it the time frame that you guess something might go wrong and the tilapia might have a die-off?
Basil and herbs are what I would be most interested in, along with hot peppers.
Any idea on how well Dill works in an Aquaponic system? Fresh dill is quite expensive up here. A couple years ago I estimated, based on what the local stores were retailing at about 38 bucks per pound.
I have had really good results with Dill, Sweet Basil and Peppers in raised beds.
the 1.25-1.75 lb tilapia were between 1.5 and 2 years of growth. I think better growth rate is achievable. these werent optimal conditions and i often stressed them out with being a newb causing them to not eat for a few days. Also consider mossies are the slowest growing of the tilapias
My 4-5 years estimate is just that is about how long I would expect a tilapia to be a good breeder. I am assuming you either add new tilapia to your breeding gene pool or start over with new breeders.
dill does great, it's in the category of vegetative nitrate type plants. I grew some in my first indoor system, honestly,it was too vigorous, invasive for my small space and i had to take it all out. Have had great success with both basil and peppers as well. Very hot and tasty. I had so many i was giving them out to coworkers and one of them pulled me aside and told me that next time i had extra to just bring them to him and he would PAY ME.
Thanks I've been doing a lot of reading on UVI. There's a full chapter on it in one of my Aquaculture books written by Dr. Rackocy (sp?) and I've seen a presentation on it.
Last edited by Cecil Baird1; 06/16/1309:47 PM.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
Isn't it a misnomer to say the fish poo is growing your plants? Isn't it more likely the ammonia primarily given off by the gills and the subsequent nitrates as a result of the nitrification cycle? Also the various minerals that are made available via mineralization? I mean after all we try and remove the solids don't we and they can actually be harmful to the plant roots.
Not trying to be nitpicky. Just asking.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
Yes, it's the ammonia, but i liked this title better than "Growing plants with fish respiration."
You are trying to remove the solids because you have a raft system and the solids can accumulate on the roots and "suffocate" the plant. I dont remove any solids in my backyard system. I let them break down i my grow beds and let the system reuse the micronutrients. The solids accumulate in the substrate and not so much on the roots. I also have red wiggler worms in my grow beds that help break things down faster.
Theoretically you could put substrate grow beds between your fish tank and rafts and do the same thing.
Yes, it's the ammonia, but i liked this title better than "Growing plants with fish respiration."
You are trying to remove the solids because you have a raft system and the solids can accumulate on the roots and "suffocate" the plant. I dont remove any solids in my backyard system. I let them break down i my grow beds and let the system reuse the micronutrients. The solids accumulate in the substrate and not so much on the roots. I also have red wiggler worms in my grow beds that help break things down faster.
Theoretically you could put substrate grow beds between your fish tank and rafts and do the same thing.
brian
Got it!
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.
I had a loss today. I wish i had done a closer picture.
This is an LMB that appears to have choked on a small redear sunfish. One month ago the LMB and redear were all about the same size, (2-2.5" long).
This was one of my largest/fastest growing LMb but there are others of comparable size. I lost a couple more redear recently that were not eaten but seemed to have trauma/bruising on their bellies. I am going to have to drain this tank and separate the red ears from the LMB asap to keep from losing more feed trained redear and hopefully stop losing LMB?
overall the LMB growth rate seems every bit as fast as any tilapia if not more vigorous.
Tomorrow I hope to post a couple of pictures of my eight cabbages growing on my pond raft for three weeks now. The potting mix is not fertilized for six of the plants while one is planted in pond muck and the last on one is fertilized with time-released granules. I thought the unfertilized cabbages would do well by utilizing the pond water which is full of life that would produce nitrates, etc, but those plants are terrible with the muck planted cabbage being the worst. The fertilized cabbage is huge compared to the other. I have no idea why the pond water didn't fertilize the other plants. I checked the plants for any bug damage and didn't see any. Many times one or two frogs will be setting of the raft so they may be keeping the plants bug free.
Bcotton and Cecil I think you are right about the nutrients being low in the pond. I have lots of plants and no FA and so it seems the plants are stealing the nutrients and starving the FA and therefore starving the cabbage plants. I would have thought the pond muck would have nutrients but the cabbage plant planted in the muck is the worst of the plants so I don't understand that. Last year I planted some of Bill Cody’s red tip eel grass in muck in my sunroom and they died. I will get the raft cabbage pictures today and post them.
