Symbi Biological

Catfish Added to Aquaponics System

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After a little bit of a wait, I finally got some catfish to help power the system. They’re really small at about 4 inches. Not sure if we should be calling them kitten fish at this stage. I’ll have to check on that. After the big fish kill from the aerator diaphragm failure, I wasn’t sure how many hybrid carp I had left in both tanks. So to make room for the catfish, I emptied the tank with the least amount of fish “stashing” most of the water from the 500 gallon tank into the rest of the system. Earlier in the day, I noticed the sump tank was low and figured if I clear the swirl filter to lose about 100 gallons, I could isolate the fish tank by closing the valves and use a pump and hose to empty it into the rest of the system saving my water. This worked out very well. After emptying the tank, I had about 20 strong souls that survived the fish kill. They were moved to the other tank that has about 40 or so fish left and then I filled the new home of the catfish with rainwater with the valves open on the tank for a slowly mixed addition. It’s exciting to have a new kind of fish although I’m not sure if they’ll be as theatrical as the hybrid carp who practically jump out of the tank for food splashing the many guests who visit Symbi. That’s always a fun little surprise. As always, I will keep you posted as they grow.

Mineralization Chamber

Aquaponics is extremely water wise. And our system is about to get a whole lot wiser. I’ve decided to add a mineralization chamber to the aquaponics system to minimize water loss from clearing filters and hopefully to increase the nutrient density of our crops. Every week or so, I flush the swirl filter and that sludge is sent to the outside and on the ground. For the longest time, I had hoped to use that nutrient rich material for composting, but I think keeping those nutrients in the system is a much better solution. Mineralizing the solids effluent will increase the availability of nutrients in the water, hopefully, raising the nutrient density of the produce and will allow the us to “keep” the water in the system instead of losing it to the ground or a compost pile. This minimizes water loss and water additions, which reduces our reliance on the well or rainwater collection. The system should be able to run solely on rainwater, which would also solve our sodium problem. The well water has 240ppm of sodium and plants like about 40ppm. In the mineralization chamber, the effluent from the filters is aerated and churned to increase the mineralization rate. After about 5-7 days, the mixture is allowed to settle and then the “clear” water on the top is siphoned or pumped back into the system. More effluent is then added to the mineralization chamber and the aeration/pumping begins again. James Ebeling, PhD and author of one of the greatest books ever, Recirculating Aquaculture, was kind enough to give me some advice on adding mineralization to my system. He said that the tank should be no deeper than 3 feet so that the aeration can remain effective in the chamber. I think I am going going to use a 1000 liter tote and see how that goes. These tanks are fairly common and I use them for large batch compost extract brewing. I’m going to use the same set up I use for the extract brewing to use for the mineralization chambers. My plan is to have two tanks although I’m not sure I have enough room. When I “flush” the swirl filter, usually around 100-175 gallons needs to leave the tank so I can adequately clear the pipes going from the fish tanks to the swirl filter. A lot of solids collect in those pipes. Having two tanks gives us the ability to deal with this volume creatively. I may need to use both tanks each time or maybe they can be alternated. It will depend on what method gives the best ability to siphon off the “clear” water to add back into the system. I’ll let you know when they get plumbed into the system. I’ve got some work to do to find the room for two more tanks in the tight fish room.

Measure to Manage-Aquaponics Nutrient Analysis Report #3

Every 6-8 weeks, I post my photometer readings for the aquaponics system water. The biggest change I’ve made this term is using rainwater exclusively. I should also add that I lost a bunch of fish in early February due to an aeration pump failing. Hoping to have more fish in the next week or so. I guess that was a big change, too.

NO3 NO2 P K Ca Mg SO4 PO4 Alkty Na Fe NH3 EC pH Temp
11/2/15

35.4

6

29

50

60

110

110

89

140

240

0.92

1.16

2.59

7.3

68.1

11/18/15

35.2

8

27.5

50

60

115

120

85

145

230

0.89

1.21

2.53

7.2

67.2

12/9/15

30.9

8

30.5

30

60

85

120

93

85

230

1.91

1.18

2.28

7.15

54

12/21/15

34.6

9

28

24

80

90

200

87

75

220

2.00

1.12

2.22

7.00

57.7

1/4/16

33.9

11

29

20

100

100

200

89

70

220

1.98

0.94

2.19

6.6

58.4

1/20/16

31.4

4

31

175

110

105

190

95

95

220

1.78

1.24

1.97

6.96

61.3

2/10/16

29

4

30.5

80

70

80

200

85

95

180

2.34

1.32

2.11

7.02

64.3

3/4/16

27.6

5

28.5

20

60

60

300

88

105

160

2.2

1.24

2.17

6.99

66

You can see, the nitrate level is a little lower since I lost most of the fish in one tank and about half the fish in the other. The best news is that the sodium is slowly going down since switching to rain water. We’ve been getting some good El Niño rains and I hope that I have enough rainwater to last until next winter to see what it is like to grow with lower sodium levels. Lettuce head quality has improved and I think it’s partly due to the sodium dropping and also because I had to add some potassium bicarbonate and calcium hydroxide to adjust alkalinity and pH since changing to rain water. It will be interesting to see how the growth goes in the next couple weeks. Having the potassium and calcium boost certainly helped and I will keep an eye on those levels. As the sodium drops, I think it will be easier to look at how the occasional additions improve growth. You can also see magnesium is slowly dropping, too. Over time, we will be able to see what the sweet spots are for each of these elements in this system. Like in the case of iron, I made two additions. One in December and one in February to get the iron to above 2ppm. In the future, I look forward to working with some of the newer organic fermented fertilizers to maybe add a boost every now and again to grow a more diverse crop. Is that cheating? Sort of, I suppose. Maybe we add some of this to the fish food formulation. It’s all up for consideration. I’m mostly interested in the health of the fish and the nutrient density of the produce to optimize aquaponics. We already know how water wise aquaponics is. Now, we just have to figure out how to tweak our methods so that we can grow the healthiest food possible. Sharing this information helps us all to see how one system is performing. Perhaps, this will inspire others to share their system info so we can compare notes to contribute to a healthy aquaponics industry.

 

 

White Worms

I just got back from the World Aquaculture Conference and learned that white worms, also known as enchytraeids, are being raised for a possible fish feed ingredient. I’m uncertain if they’ve been made into a meal, but eager to learn more. I met two nice professors that are working with white worms and learned that the former Soviet Union used to raise them for white sturgeon production. There’s even an out of print book the Soviets wrote that seems to be the only information on culturing white worms for feed production. Elizabeth Fairchild, Ph.D. from University of New Hampshire offered to send 10 grams of white worms to anyone who would like to participate in learning more about their possibility as feed if you fill out an online survey afterward. I couldn’t raise my hand fast enough. White worms look like a great addition to the Symbi loop. In fact, they’re already a part of it as they are in the vermicompost. In my cricket production, I make mud pies for the crickets to lay eggs and to get a drink. I make the “mud” from one part vermicasting to four parts coco coir. Everytime I scoop up the castings, I see some white worms that are headed into the cricket bin and presumably gobbled up soon after. I’ve been raising them all along! I’m going to experiment with feeding them live to the fish. And then concentrate on culturing them to see if it is a viable alternative to fish meal. I’ll be sharing the whole process as it progresses.

Lettuce Inside

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I’ve been feeding the crickets lettuce discards and they really like it as you can see in the photo. I peel off some of the outer leaves from the heads during harvest and save the for the crickets or the worms. I also try to tap any aphids I find into the pile of cricket bound lettuces for some extra sweet treats. I don’t really know if aphids are like candy, but ants sure do like them for the honey dew they excrete out their back ends. Aphids have these things called cornicles that are like dual exhaust pipes. Only they emit sugary carbon instead. I’m making a wild assumption they are sweet little morsels that pop in your mouth like caviar, but I’m not brave enough to find out. The lettuce provides the crickets another water source and nutrients. It’s nice because it dries up before the mold can get to it making it a safe addition to the cricket bin.

96 Countries 

  
Wow, it’s pretty crazy to know that 96 countries read this blog! I started this to share so that others who are interested in fish, plants, bugs, pasture, and compost could learn from my mistakes and, hopefully, some of my successes. I love reading other blogs about what people are working on and have always appreciated an honest approach that includes failures along with achievements. Most importantly, a blog that has fresh material at least every couple weeks or so. Thanks for reading symbibiological.com and if you ever want to reach out, my email is doug@tomkatranch.org

Aerror

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A couple days ago, I found the majority of my fish belly up. Not a good sight to see. My first call was to our friend Fred S. Conte Ph.D. Extension Aquaculture Specialist at University of California, Davis. He knows just about everything and everybody in the fish world and is a pretty neat guy to have in the aquaponics industry. Since almost all of the fish died at once, he figured it might not be a pathogen. Perhaps something mechanical?

Just after our conversation, I determined that the diaphragm in the air pump failed and there was no aeration in the fish tanks. They all died of suffocation. An incredible bummer, but a great opportunity to investigate a couple of things. First, after knowing it was a mechanical issue, it would be a really good idea to look into battery back up systems for the air pumps and water pump so something like this doesn’t happen again. Although, in this case, a simple battery back up would not have prevented the fishkill from happening since the pump motor was running just fine. As I mentioned above, it was the diaphragm that pushes the air through the tubes that failed. Adding a pressure switch to the battery back up would probably do the trick. I’ll let you know what we build.

Secondly, if this fish kill happened to be a pathogen, what would be the protocol to send them to a pathologist? Fred introduced me to Esteban Soto, MSc, DVM, PhD, Dipl. ACVM, CertAqV, Associate Professor of Aquatic Animal Health, Department of Medicine & Epidemiology, School of Veterinary Medicine, UC Davis. I’m excited to work with Esteban to see if we can develop a protocol for aquaponicists in our region to send their fish to the lab for a diagnosis.

So what happened to the fish?

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As much as I would’ve liked to have kept them in our little loop, we had to act fast and I don’t have enough freezer space for 400 lbs of fish! Mostly, because the freezer space I do have is occupied by frozen crickets. So we had to take them to the neighboring farm where they will be consumed by their chickens.

Ideally, we would’ve been able to keep the fish to dry and grind them to make our own fish meal or even feed some of them to soldier fly larvae. The black soldier fly larvae project got put on hold due to the crickets taking up a good portion of my time, but it is going get restarted very soon now that I have the crickets going full swing. They would’ve loved the fish! My hope is to get a grinder soon so that I can grind a whole bunch of different things to make feed. That’s all part of the master plan. Until then, I’m grinding by hand. Just not 400 lbs of fish by hand. 🙂

Now I gotta get some new fish!

Compost and Pasture

Cows on pasture seems like a pretty simple system. Cows eat grass and their manure helps feed the soil which helps the grass to grow again. What many ranchers have found is that if you plan the grazing to give enough recovery time for the grass roots to grow back, you get healthier pasture and can actually grow soil as a result. So how does that work?

When a grass plant is bitten, the roots recede to power the leaf growth. In a planned grazing system, we allow for the recovery of the roots so that growth is regenerative. In a conventional pasture, where the cattle are allowed to roam anywhere they want, the grass plants can get stunted due to over grazing. As I mentioned above, when a grass plant is bitten, the roots shrink up to give the plant energy to grow the leaves again. If the grass is bitten before the roots recover, the roots try and provide the growth again, which shrinks them even more. Since there wasn’t much energy left in the recovering roots, the grass can only grow a little bit. Eventually, the grass plant becomes stunted and the pasture underperforms. Little roots and little shoots equals stunted pasture.

Healthy grass does a number of wonderful things for the ecosystem by providing root exudates for the soil microbes to actually grow soil. Root exudates are sugars, organic acids, and other carbon compounds that the plant sends through the roots to provide the bacteria and fungi an incentive to deliver much needed nutrients and water to the plant. Carbon is the currency that plants use to grow. As this process plays out, carbon is extracted from the air through photosynthesis and the plant sends it into the ground. This is a really powerful process that builds the organic matter in our soils and sequesters carbon. By increasing the carbon in the soil, we are decreasing it from our atmosphere and, as we can see, Carbon dioxide has been increasing in our atmosphere ever since the industrial revolution. As we burn fossil fuels and over till soils, we are releasing it into the atmosphere and the ocean can only absorb so much.

One way we can balance this out is by growing topsoil through the use of techniques like planned grazing practices. Giving enough time for the roots to recover keeps the incentive system working. The microbes are happy, the plants are happy, and in turn, the cattle are happy. All while pulling carbon from the air and putting it in the ground.

All of this is great stuff, but in some cases where the land has been mismanaged or through some other undesirable type of environmental condition, the land might need a jumpstart to get back to good health. Marin Carbon Project has been doing some amazing work with applying compost to rangelands and found that just one application of 1/2” of compost to a pasture can assist the pasture plants in getting the party going underground again stimulating growth, increasing water holding capacity, and most importantly, carbon sequestration.

We are experimenting with applying compost to our pastures in combination with planned grazing to see how this will improve the performance of the land. We started applying the compost on the land about a month ago and then the el niño rains hit us. We are hoping to get more compost out into some other trial areas once we can get back out into the soggy pastures. We believe that through MCP’s great work and with the planned grazing, we can possibly increase the carbon sequestration and performance of the land as a win-win for everyone involved. From the smallest organisms to the big bovines, everyone has a job in the ecosystem. Stay tuned as we work with our friends from Point Blue to help us monitor and record the results here on TomKat Ranch. We’ll share what we find!

Not So Many Critters of the Worm Bin

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When I first started this blog, I made a video called Critters of the Worm Bin. It is a worm’s eye view of all of the different critters you will find in a typical worm bin. Pill bugs, sow bugs, carabids, mites, spiders, flies, etc. There’s even a very graphic scene where a pill bug is caught eating a worm! A once in a lifetime shot, if you ask me. I couldn’t believe I caught that on film. Nowadays, there aren’t so many critters left. The spiders took care of all the flies and became a big player in my Integrated Pest Management team. Now the spiders are gone and it’s mostly worms, the pill bugs, who are surprisingly omnivores, and Pacific Tree Frogs, who came on the scene about year and a half ago. Over that time, the frogs have eaten the rest of the critters! Except for the pill bugs and sow bugs, who must not be very tasty or nutritious. I suspect the frogs are eating some of the worms when they surface, but I’ve yet to catch one in the act. Sort of figured I would see some evidence of them digging if they were really after them. They’re really cute and the worms seem to be fine, so I’m not going to evict them just yet. After all, they are leaving the pill bugs and sow bugs, who do most of the heavy lifting in the system by breaking down the horse manure and discarded lettuce form the aquaponics system and then the bacteria and fungi take it from there. The worms eat the bacteria and fungi. I’ll keep an eye on the froggies and, hopefully, they can stay in the wormery without wearing out their welcome.

Crickets and Water

IMG_8628After my successful string of harvests, I learned from our friends at Bitwater Farms that we can get even heavier yields from the kind of bins we use. We should get closer to a pound per bin, which is well above the half pound average so far. I’ve been harvesting at about 6 weeks and probably should wait until 8 weeks. With the holidays and being a little shorthanded, I figured what better time to give it a go. Well, the extra two weeks gave them time to eat each other and created quite the mess in each bin while lowering the overall yield to about 6 ounces per bin. 😥

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