Food for Tilapia

There are several options for feeding your tilapia depending on the size of your operation and the format of your grow environment.  This entry will focus on systems that have the fish in enclosed tanks.  This is as would be found in a city backyard system.  For reference, the use of large outdoor ponds is a different system that has other options.

General feeding issues.
You want to feed your fish for maximum growth and least waste.
Your fish can go with less food or no food for a couple days.
It is better to underfeed than overfeed when you will be away from your setup.  Overfeeding will lead to water fouling and fish kill.
Feeding your fish too much will result in undigested food travelling through their system, and inefficiency.

Starting:
If you are just starting; you have "started" your tanks and you are awaiting the delivery of your fingerlings; these are good places to get food:
http://premiumfishfood.com/
http://jimsfish.webs.com/fishfood.htm

Once you are going, you can experiment with different foods.  You can grow your own algae, make your own food or even use kitchen scraps.  Be slow in scraps you put into your tank to ensure you don't foul the water (eg. oily muffins are bad, bread can be good if used in moderation, raw vegetables can be good).  I found tofu to be a welcome food by the fish.

Ongoing and Recipe for your own food:
Purchased bulk food:
A good, reasonably priced food for your grow tanks is Purina Game Chow.  This is available locally at Tractor Supply Company.  It is variably sized and works well with both my auto feeders.

Tofu:
Tofu can easily be made at home. The most difficult part is making soy milk, but you can do this easily now with "soy milk cookers".
An example of a good maker is here,
SoyJoy Soymilk maker
Once you have made soymilk, you add a coagulant (calcium sulfite, or magnesium chloride) put in a press to remove excess water.  You can get food grade ingredients from http://www.soymilkmaker.com/order.html

Further instructions are here,
http://www.soymilkmaker.com/making_tofu.html

Cream of Wheat Cakes:
While I was investigating making my own tofu, and pondering the coagulants used in that process, I began experimenting with alternate recipes.  What I settled on and use regularly is the following. It came from the thought of making tofu, but instead uses other readily available ingredients.
1 cup instant Cream of Wheat
1 cup of medium burr ground soy beans
1/2 cup of ground corn meal
1/2 cup of finely cut dry seaweed
Begin making the instant cream of wheat per the package instructions.  Immediately after pouring in the cream of wheat, also add the ground soy beans, corn meal and dry seaweed.  Continuously stir so it remains smooth and does not burn.  Once the mixture begins to thicken turn off heat and cool for about 10 minutes (until still able to pour, or scoop).  I scoop the mixture into used tofu tubs with a spatula, pressing as I go, and then allow to further cool.  Cover with plastic wrap and place in refrigerator.  To use, cut rows and columns into block so that you can remove a square column and feed to tilapia.

Automatic feeding:
I use two types of auto feeders.  I use smaller units for my 55gal and 110gal tanks, and a larger unit for my 300gal outdoor setup.  Both feeders dispense 2-3.5mm circular pellet food (the Purina Fish Chow).

For my indoor tanks I use an Eheim Air Feeder.  These provide about a week of capacity and are reliable. I have a complete review here,
Amazon Review
Purchase from Amazon

For my outdoor grow out tank I use a Super-Feeder ASF-1 unit. I have modified my unit with an extra carrier to hold a little more than 1 week of food.
Super-Feeder Fish Feeder

Reference:
http://seagrant.uconn.edu/whatwedo/aquaculture/pdf/ncrac114_tilapia.pdf
Aquaponic Gardening by Sylvia Bernstein

Aquaponics:fouling water and other problems

Problems to be encountered in Aquaponics systems:
* predators: raccoons, opossums, they will eat your fish or destroy your grow beds looking for snails
    --> mechanically protect: cover fish tanks, enclose system
    --> simple styrofoam has shielded my system from these predators, though they did cut through my plastic door before I put foam on it also

* sludge fouling your piping and grow beds
    --> use a sludge separator: http://wolfenhawke.blogspot.com/2012/09/aquaponics-sludge-separator-update.html

* water fouled: this could be for any number of reasons, but most likely it will occur from overfeeding.  This can happen accidently due variations in an auto feeder
    --> turn off all feeding until water clears, don't worry, your fish can survive days without food
    --> if you see excess floating food, remove it
    --> if possible replace at least half of your water, but don't fret it if you cannot replace
    --> if you are using a timer on your water pump, bypass it so it is running 24/7
    --> run the system continuously until the water clears -- it will, then restart normal operation

* mysterious fishkill:  your fish are dying but the water is not cloudy
    --> this is rare for tilapia farming
    --> check your chemical levels
    --> check for dead fish fouling the water
    --> check the tank temperature -- sometimes heater elements will fail on
    --> check for water getting too cold -- temps lower than 55F are bad for Tilapia
    --> proceed similar to water fouled actions above: but on chemical imbalance, you will also need to investigate -- this could happen if you didn't "start the fish tank" and you put a lot of fish in at once, see http://wolfenhawke.blogspot.com/2012/10/starting-fish-tanks.html

 

Starting the Fish Tanks

First of all, a little primer on fish tanks.  They are an ecosystem creating a nitrogen cycle.  The fish eat food and expel nitrogen and feces which decompose and create more nitrogen.  There are two types of bacteria that live in a healthy fish tank that convert the nitrogen first to nitrites and then to nitrates.  Too much nitrogen or nitrite in the water will kill fish.

The filter in most fish tanks does a little bit of mechanical filtering, but it's primary purpose is to house the bacteria that is essential for the nitrogen cycle.  Thus if you thoroughly wash your filter every week because your water is getting cloudy, then you are in a constant wash cycle and are not getting your fish tank where it needs to be for your fish to be healthy.

You can read more here:
http://www.diyaquaponics.info/bacteria.html
http://fins.actwin.com/mirror/begin-cycling.html
http://www.algone.com/articles/aquarium-filtration/nitrogen-cycle

Nitrates are readily absorbed by plants for their nutrient uptake. This is the lynch pin in making aquaponics a self sustaining ecosystem.

I started my aquaponics tanks using clear ammonia and putting some extra operational filters from my indoor fish tanks into the aquaponics tanks (for bacteria transfer).

Monitoring Aquaponic Grow Bed Water Levels

With ebb and flow water systems, it is useful to monitor your water level under the surface of your grow media.  This is a simple but effective method do that.

As you are filling media into your bed, put a length of 1.5" PVC pipe in the bed vertically in the media.  Allow the top to protrude above the media surface by a good 2 inches (5cm) at least.  If you are using fine media, it would be good to attach some fiberglass screening with plastic lock ties at the bottom of the pipe.

Now make the indicator using a straw and a piece of styrofoam that is smaller than the diameter of the PVC pipe.  Say about 1.5cm in width.

 Picture showing styrofoam with straw embedded.  Note the graduations marked on the straw.  This is long because I use deep grow beds in my setup.

Picture showing the level meter in operation.  Water filling the grow bed is causing the indicator to rise.

Salads with Ebb and Flow? YES!!

In aquaponics systems, salad greens are normally grown in a flow or flood system with the roots continuously in running water.  I have a deep bed ebb and flow system and recently populated one bed with mesclun salad mix seed.  I used the vermiculite bed for the salad greens.  Please see http://wolfenhawke.blogspot.com/2012/10/aquaponics-grow-beds-and-media-stackup.html for various media stackups.  Seeds were just spread on top of the fresh vermiculite.

The following picture is a successful yield offered by this method.

Bell Siphoning for Aquaponics Grow Beds

Aquaponics systems use one of two water recirculation systems primarily.  One method is the "flood system", "flow system", or "constant flow" system.  This system runs the water continuously through the root systems of vegetables.  The other method is the "flood and drain" or "ebb and flow" system.  This system adds water to grow beds causing the water level to rise to just below the media surface, and then drains the water and repeats the process continuously.

Flow systems are good for salad green farming.  Flood and Drain systems are good for all types of vegetables but are a little more complex.

As you have seen from my setup schematic, http://wolfenhawke.blogspot.com/2012/10/single-pump-aquaponics-system-design.html, I use Flood and Drain in my system.  This is accomplished by using a bell siphon in the grow bed.  This apparatus does not use energy but counts on vacuum created in a sealed water system.  There is plenty of information on building your bell siphon.  One paper is available here, http://www.ctahr.hawaii.edu/oc/freepubs/pdf/BIO-10.pdf.

Since my grow beds had a drain plug on the side, I used this. I do not recommend going from the side as the setup is more complex to tune, but I am showing this for interest/information.  Certainly, you can setup your similar beds with the draining straight down.

As you can see, my internal standpipe makes a 90 degree bend which is non-standard.















After that the bell pipe is installed on the standpipe.  Note, one disadvantage with the 90 degree standpipe connection, is that the bell pipe cannot seal as far to the bottom.  The top of the cut at the bottom of the bell pipe determines the minimum level of water in the grow bed.  My bed will have about two inches of water always at the bottom.

After this stage, you can fill the planter with your media.  As you can see, one benefit I do have with the 90 degree install, is that I can tune the height of the water draining by turning the bell pipe and standpipe as a unit.  I had to do this on all my planters to get the desired height -- this is likely because I do not use "snorkels" on my bell pipe and the trapped air is compressing and affecting the rising water level.

Single Pump Aquaponics System Design

I use an architecture in my aquaponics setup that requires a single pump per fish tank used.  This minimizes electricity and vastly reduces the complexity of the control system.  The water is pumped to my sludge separator design (see blog for details) which is at the highest location in the system.  Gravity is then used to move the water from the separator to the grow beds and back to the fish tank.  Using more than one fish tank in the same system requires balancing the effluent water from the grow beds and this will be addressed in another article.

The schematic of the setup is shown below:

The fish tank is shown below:

 













The sludge separator is shown here.  The pipe on the right is the influence. The pipe protruding from the front is the overflow back to the fish tank (a safety measure).











Here the piping is shown from the grow beds (3/4") to the collector (2") which returns the cleaned effluent back to the fish tank.

Since I use flood and drain as my water distribution, I could technically just keep the water pump running. I use drains on the side of the grow beds.  This side draining is much less efficient than bottom draining and what happens is that the water slows down in draining as it gets to the bottom of the bed.  This causes an equilibrium to be reached if the water pump is left on all the time.  At equilibrium the water is about 1/3 depth in the grow beds at all times.  I alleviate this problem, and save electricity to boot, by putting my water pump on a timer that runs 30minutes on, 30minutes off continuously.  This means I only pump half the time. It also allows the grow bed to get flooded and drain once per on/off cycle.

I have not had trouble with the side draining, but it does take a little tuning of the bell siphon.  We will cover this siphon design on another article.

Aquaponics Grow Beds and Media Stackup

Aquaponics is the raising of fish (for food) and recirculating the water through grow beds to grow vegetables (for food).  The ammonia that increases in the water in the fish tank is converted to nitrite and nitrate through the same process that occurs in a successfully operating fish tank.  In a display fish tank, this conversion occurs in the media in your filter and other areas (under the sand).  It is important to note that your fish tank filter's primary purpose is providing the media for the nitrogen cycle bacteria to thrive.  In aquaponics, this media is the material used to grow the vegetables.   The benefit of this is that the vegetation gets the nitrates they require directly as part of reducing the poisons in the fish water.  Thus you get a closed nitrogen cycle system.

On the post, Freeland-fp100-as-aquaponics-growbeds  I noted the Freeland bins that I use for my deep root grow beds.  On this post I will describe the stackup I use for the media.  The pictures below show a bed with hydroton as the top layer and one with vermiculite as the top layer.




The beds after being cut are 20" deep.  The bottom 6" are washed 3/4" gravel.  There is a long air stone buried in the bed at this point.  This is optional to have, but I wanted to inject air here to prevent any anaerobic bacterial action here.  A summary of the stackups I use is drawn below.

In some beds, I use Hydroton for the whole top layer (about 6" total depth).  In some I use about 4" of Hydroton and 4" of vermiculite.

The reason for the vermiculite is for seeding directly and for a variety of grow media depending on plant preferences.  Fine seeds work very well directly in the vermiculite.  I have had success with mixed salad green seeds, as well as tomato and cee gwa in the vermiculite.  I have had success with cee gwa directly in hydroton also.  In general for the hydroton beds, I start seeds in coconut husk pots filled with vermiculite.

The vermiculite really encourages robust root growth.  When harvesting often the top 3" of vermiculite is saturated with root (especially when growing tomatoe) and this must be disposed of and replaced with fresh material.  Below is a photo of vermiculite saturated with tomato root.  Also is a photo of cee gwa roots that were grown in hydroton.

Salad growing in a vermiculite bed:

Aquaponics Sludge Separator: Update

This is an update to this post: http://wolfenhawke.blogspot.com/2010/09/aquaponics-sludge-separator.html

In June my aquaponics water feed pipes started having a lot of sludge.  On inspection it turned out that the plexiglas wall had come loose from the sludge separator.  This was great evidence of how helpful this simple equipment was.  The loosening of the plexiglas was likely due to the expansion of the plastic bin when loaded with water causing stress on the sealant. 

The solution was to mechanically attach the plexiglas.  This was accomplished with the white rectangular implement shown on the top of the bin in the first photo.  Using these nylon items along with nylon screws ensured that no metal would be imparted into the aquaponic water system.  Any such fastening technique can be used -- I got these particular parts from Orchard Supply Company.

I did a modification to the original design at this time putting in a second bar at the influence that would cause the water to "roll" over it and onto the plexiglas.  The effect of this is material is improved sediment trapping in the first compartment.  Note the lengthened effluent pipe was removed eventually -- it did have the interesting affect though of allowing the depth of water in the second compartment to be set (due to the vacuum affect of water leaving).

Don't Bother with Over-wintered Tomatoe Plants

On an earlier post I noted that my tomatoe plant from last year was growing well in the greenhouse.  The plant continued to grow very well and did a great job as an aquaponics water filter, but it was a complete failure as a tomatoe factory.  I removed the plant from the grow bed several weeks with nary a tomatoe harvested.  The following pictures show the size the plant got to (yes, that is a single plant) and the size of the stalks once removed from the planter.

Conclusion: don't bother with your tomatoe plants that survive past the first year.  Plant new ones.

On a related topic, overwintered bell peppers do very well continuing to produce.  You can see the bell pepper plants to the left on the photo of the tomatoe stalk photo.

Gazebo to Greenhouse: Roofing

The roof of the greenhouse is made of Solexx XP paneling.  Note, the roof elevator frame is removed.  This is a piece of metal framing on some gazebos that allows dual layer canvas roofing that provides air venting.  With this removed the roof frame is a single level, though I had 4 protrusions from the elevator frame.  I tried turning one of the original roof frames upside down so the protrusions wouldn't get in the way of the paneling, but the frame is not suited for that.  I got one to work, and just left it.

The paneling is cut to appropriate lengths and then placed on top of the metal frame roof.  Some geometric planning, and careful measurement is required here for a minimally seamed solution.  I allowed for spaces between my seams and covered them with pool covering insulation.  The XP panels I used are dual pane with an air insulator pocket in between. These are stiff enough that they can be attached to the metal greenhouse frame with zip ties.

The insulation I used for the seams proved to not be very UV resistant, so I am updating the seams with the UV greenhouse plastic used for the upper walls.

Other posts in this series:
Pictures More Pictures
Start
Insulating and Doorway
Upper Walls
Door
Roofing

Gazebo to Greenhouse: Update: door

On an earlier post you saw the framing of the door for the greenhouse.  Here is a picture of the finished door.

This is wrapped in pool insulating plastic which is actually not very UV tolerant, but it works fine for the door.  There is an interesting point I would like to make.  The greenhouse is really framed on the lower half with about 3/4" foam.  

The door is just plastic wrap.  I have racoons and opossums in my neighbourhood -- not many but they are here.  For some reason they don't bother trying to get through the foam -- maybe it's the foil cover on the outside? Don't know. They can obviously smell the slight fishy water that is in the greenhouse.  Well after about 8 months I did have infiltration of the greenhouse -- through the door -- they scraped back the plastic cover on the bottom and walked right in at night.  Only damage thankfully was rummaging through one of my planter bins for snails -- the creature did not attempt to get into my covered fish tank.

I put some of the insulating foam on the lower half of the door to dissuade the critters, and just for insurance also attached 1/4" wood on the outside bottom of the door -- that has kept the kritters away.

The door uses a gate latch system.











An update picture is shown here also of my 2012 tomatoe and Cee Gwa (both started from seed directly in this bin -- this is the seed starter bin).

Other posts in this series:
Pictures More Pictures
Start
Insulating and Doorway
Upper Walls
Door
Roofing

Gazebo to Greenhouse: Upper Walls

This is the third installment of the greenhouse creation from my gazebo frame.  At this point we have a doorway and insulated lower walls.  The upper walls will be made with greenhouse plastic (UV stabilized clear plastic).

The upper walls are constructed by screwing 1" x 0.5" strapping to the top horizontal metal bar of the gazebo.  The upper "walls" are actually curtains made from 4 year greenhouse film cut to be just longer than the upper half of the greenhouse.  The film is treated with a bead of silicone glue then stapled to the wood strapping with a strip of heavy cloth material. I used 1" tow straps bought at a surplus store for the "heavy material".  Put a UV resistant length of rope at the center of each curtain so you can tie the "wall" open during summer months.

In order to anchor the sides of the walls, I screwed lengths of "Snap Clamp" material along the side.  The clamps were screwed either into the wooded door frame or metal sides of the gazebo.  The clamps work by allowing you to sandwich the film between the clamps and short lengths of 3/4" PVC pipe.

I purchased to Greenhouse film (20ft wide x 25ft long) and (10) 48" lengths of snap clamps from www.greenhousemegastore.com.  I also  purchased 33 linear feet of Solexx XP for the roofing material as part of the same purchase.  Total including shipping was $403.37.



Other posts in this series:
Pictures More Pictures
Start
Insulating and Doorway
Upper Walls
Door
Roofing

Power Failure Tolerant Air for Aquaponics Fish

I run two high capacity air pumps for my aquaponics fish tanks and grow beds (some of my beds I pump air into).  These are 110v air pumps.  They will run off a large car battery and inverter for about 36 hours.

To make the system tolerant of power failures I do the following:

1. Power a battery trickle charger from mains 110v -- this can supply the 60-90W required for the air pumps.
2. connect the battery to a 150W inverter
3. power the air pumps from the inverter

Now the battery is maintained at full charge while my mains power is on (99%+ of the time).  Should I have a power failure for a storm or other reason, the battery would still power the air pumps for more than a day. My water starts getting messed up if the water pump doesn't run for a day, so this is about the time I would have to take other steps.

Second Year Tomatoes and Green Peppers

I overwintered one tomato plant and all my bell pepper plants in the aquaponics greenhouse.  This is what they looked like in May of this year (more than 12 months old).  I wasn't certain in May if the tomatoes would set fruit.  They had plenty of flowers but no fruits.

I am not actually sure if the tomato didn't eat any visitors to my greenhouse (just kidding) :-).  That is one plant.

This last weekend I harvested about 40% of the bell peppers (all the red ones, and many larger green ones). While trimming back the tomato plant I also noticed that it had set some fruit.

The smaller peppers were perfect for BBQ skewers.

Conclusion, yes overwintered tomatoes and bell peppers will yield.  The bells are yielding very well. It will remain to see at years end if the tomato yields well.  The tomato plant is certainly very healthy and is a good anchor for my water filtering needs.

Converting Outdoor Transformer Lighting to Solar (p1)

I use 3x 18W lights to decorate my front yard.  This is a total of 4.5A at 12v.  During a recent visit to Anchor Electronics (www.anchor-electronics.com) I found blade style LED high power LED lamp assemblies.  These lamps are built on a PCB consisting of 6 LEDs, a discrete rectifier (to prevent polarity on connection), and a power management chip.  My immediate thought was to convert my 18W lamps to this LED lamp.  Each lamp uses 20mA.  So in total my yard lighting would be 60mA instead of 4.5A.  This is more supportable with a battery backed solar setup.

I started the experiment of determining if this would work by converting one burned out bulb to take this lamp.  The following pictures show the steps but read the end instead of following this.  First I taped up most of the glass of the bulb.  Using a plastic wrap I made a base to hammer the bulb to break the top of the glass (without the base, the actual base of the bulb would get damaged).  Next I uncrimped the tungsten and crimped on the pigtails of the LED lamp holder.  I solder gobbed the crimp connection (I believe in belts and suspenders for my electrical connections).  I had o solder gob instead of solder because the tungsten carrier is not easily soldered to.  Finally I filled in the space in the lamp with non-conducting plumbers putty. Installed the LED lamp and fired away.  OK, it took more debugging to get this to work as it turned out that pushing the LED lamp completely into the holder shorted the diodes and prevented operation -- so the LED lamp assembly needs to be pushed in but not all the way.

As it turns out this worked very well.  The 20mA unit was about 75% (qualitative) as bright as the 18W incandescent bulb.

If you want to do something like this, an easier way would be to source the parts from:
http://stores.ebay.com/Auto-Gangster-2009?_trksid=p4340.l2563  -- i ordered parts from here
http://stores.ebay.com/id=1007915828    -- have not ordered from here
http://www.superbrightleds.com/  -- have not ordered from here

After I get my COTS lamps, I will work on converting the transformer system into a solar powered setup instead of mains powered.  Stay tuned.

Wine Cellar Update

Operating within design parameters.  I keep it at 58F.  Duty cycle is low.  The left view is the cork encrusted door.  We'll see what the duty cycle gets to in the summer months.

Previous posts:
http://wolfenhawke.blogspot.com/2011/10/wine-cellar-update.html
http://wolfenhawke.blogspot.com/2009/08/update-on-wine-cellar.html
http://wolfenhawke.blogspot.com/2008/09/finished-conversion-of-unused-closet.html

Night Fennel harvest

I learned from UC-Davis that Fennel root grows well in California.  I planted this from seed in the greenhouse over the winter.  This is the second harvest of my roots.  This done at night while I was cooking some curry.  The root can be cut into 1" slices and baked with olive oil and balsamic vinegar. The stalks can be cut and used like a feathery celery.  I cut stalks up to 1cm lengths and put half of one roots worth in to a curry. The baked roots are delicious and all the parts have a slight anise flavor.