Daily, Weekly, And Monthly Tasks In A Commercial Aquaponics System
Daily Tasks:
Feed The Fish:
The fish food we use is Rangen 1/8” floating catfish food. You can use any floating food that has about a 30% protein, 6% or more fat content, but TRY to find a fish food that comes in the nice small 1/8” pellet size, as we have noticed problems, both with acceptance by the fish when they were fed larger sized pellets, and with the growth rate and health of the aquaponics system. Feed your fish three times daily, morning, noon, and 1 hour or so before dusk. Feed ad libitum, which means as much as they will eat. When you first feed a group of new fish, start feeding a little bit at a time until you are sure how much the fish will eat. Check back in 15 minutes after feeding to see if the feed is all gone, if it isn’t, it means you need to feed them a little less next time. If they eat it all in 5 minutes, you need to feed them a little more next time.
Water Testing, Measurements, And Recordkeeping:
When we began this adventure, we were nervous and inexperienced and checked water quality twice a day. We ended up with a simple form to fill in when feeding the fish in the morning (below). We check ammonia, dissolved oxygen, and nitrites/nitrates two or three times a month now, and this is useful information. If you are observant, it is immediately obvious if something changes or is wrong. The best thing about keeping records is that you can look back and correlate some event in the vegetables with some event that happened with the fish and be able to tune your system to get desirable events to happen more often, and undesirable ones not to happen at all. We can tell what’s happening now by just looking at and sniffing the water (Tim drinks it!), and we still do record keeping, but we are far more relaxed about it. Our record form looks like this:
Daily Check List Date:_______Time of Day:__________
System DO Temp pH Ammonia NO2/NO3 Feed Morning
#1
#2
#3
Breeding Tank 1
Breeding Tank 2
Check mesh screens in fish tanks: 1 2 3
After 1/2 hour, check for uneaten feed in:
#1 #2 #3 Breeding Tank 1 Breeding Tank 2
You know the quantity of vegetables you harvest; weigh your fish harvests so you know how many pounds of fish you are growing as well. Keep track of how much fish food you go through; by comparing this with your fish sales in pounds you will know your feed conversion ratio, or how much food over the life of a fish it takes to make one pound of fish. Why is this useful? If you notice your feed conversion ratio is 5.4, when you know it should be around 1.7 for tilapia, you know you need to find out where your feed is disappearing.
Keep good records. If you go to a bank or even a relative for a loan, they will want to see complete, impeccably kept records as part of your application. Well-kept records also keep the IRS from assuming the worst and making you pay for it if there is ever a question about your taxes.
Checking/Cleaning
Check all filters in the system with a casual eyeball whenever you pass by. Filters or screens will flow just fine then clog and overflow in what seems like a very short time. A plastic bag blows in on the wind, someone drops a couple of net pots full of coconut fiber in a tank accidentally and it winds up on the filter. A sure sign that something needs cleaning is when you see water coming down the hill from the aquaponics!
Weekly Tasks:
Harvesting Fish/Restocking/Carrying Capacity of System
We harvest when people call and come to the farm for fish. This is easy because we don’t have to deliver or spend time selling off the farm. You can harvest the fish as often as you want as long as you don’t over-harvest and cut off your fertilizer supply (we don’t know how low this is; we are pretty certain it is a lot lower than the 0.3 lbs. of fish per square foot of raft which works well in our LD systems). We estimate how much fish is in the tank and try not to let the total weight of fish in a 1,024 square foot system get less than 200 lbs. or over 800 lbs. Remember: you can always feed 800 pound of fish the same amount of food you feed 300 pounds of fish to keep your ammonia down!
We use a simple fish size-grader made of PVC or a net to crowd the fish into one part of the tank, then scoop-net out what we want. We try to get the bigger fish because they grow slower and eat more food than the smaller fish per pound of weight they put on. If we harvest 10 fish, we restock with 11 smaller fish (at least 2-1/2″ long) to replace the fish we harvested plus 10% to account for any mortality.
Harvesting Vegetables/Replanting
We harvest and pack our vegetables two days a week, pretty much an 8-hour day each time for about 5,000 square feet of system; this takes four people each day. Then we replant, which includes seeding the new net pots, putting them into the sprouting tables, and taking the more mature seedlings in net pots from the sprouting tables and transferring them to the rafts. This takes two people about four hours each day, two days a week.
Nutrient Adjustment
You can sometimes raise the level of nitrates in your system by feeding the fish more, up to a certain point: you can get nitrates up to 5 to 10 ppm with some additional fish/feeding, but if you try to raise them more than that, the only thing that increases is your ammonia level. If you continue overfeeding in an attempt to raise the nitrate level, the nitrate level will simply stay the same, while the ammonia level will increase to the point that it inhibits the nitrifying bacteria, and you will actually see a decrease in both nitrite and nitrate levels. Stop feeding the fish so darn much!
We don’t know (no one knows; at least not yet) the minimum levels of nutrients on which these systems will function adequately, nor for how long. All our systems have operated on the same extremely low levels of nutrients (0 to 3 ppm nitrates, consistently) in a stable manner for so long that we no longer worry about them. If your vegetables are growing well, don’t worry about what the nitrate level is.
Monthly Or Longer (But Sometimes Shorter)
Maintenance/Repairs
After four and a half years of operation of our commercial systems, we finally had a blower motor that needs a new capacitor. Our ice machine and refrigeration (walk-in refrigerator) has needed maintenance a couple of times in the six years we’ve been in operation. We have some corrugated galvanized steel fish tanks with the 25-mil food-grade vinyl liner; the liner developed small holes from small children whacking it with sharp objects after three years. Partially draining the tank and putting “Gorilla Tape” over the holes fixed this. Other than that, we haven’t had an equipment breakdown, and all troughs and fish tanks are holding up well.
In smaller systems such as the Family System and MicroSystem, what will fail is the water pump and air pumps. They don’t give you lots of warning, they simply quit. It’s a good idea to check your system with a walk-around twice a day to make sure the water and air are both flowing, and to have a spare air pump and water pump available. If you really want to do it right, install the spare air pump onto the airline, but don’t turn it on until the first one breaks. Then get another spare right away!
We also noticed signs of dry rot on the outsides of two first-generation plywood-epoxy-fiberglass tanks that we DIDN’T coat with HiBor water-based wood preservative before painting (after six years of operation); we removed and replaced those sides. We now use three coats of a good oil-based paint on top of the borate-based wood preservative when we build plywood/fiberglass tanks, and have recommended this in our manuals since 2009.
I’ve seen similar reliability in my own system which is much, much smaller than these commercial systems.
My daily tasks (5 minutes, if that)
-Check the battery status, fuses, energy tally for the day (all powered via solar)
-Check the sump tank water level, top off if necessary
-Feed the fish, once or twice a day
I check water chemistry once every three weeks or so now that its cycled. I’ve gone for a month without doing anything other than throwing feed in the fish tanks on the way out the door to work.
Truly, it has been growing on cruise control. It has been hot this year and a friend with an elaborate, traditional backyard garden showed me drooping plants telling me he’s been forced to water multiple times per day. I have off grid pumps on timers set to 10 minutes every two hours, so I don’t actually have to worry about it at all- no real garden maintenance to speak of. I will prune plants from time to time, and “steer” things like cucumber along a desired path.
When I go on vacation, I’ll add an automatic fish feeder or something. I do want to have automatic fail overs in place for pumps, and some kind of system health notifications in place, and will probably develop those soon.
Anyone who doesn’t want the maintenance of traditional gardening can grow this way.
On the topic of fish food, at what point in the fish’s growth cycle to you feed them the 1/8″ pellet food? What do you feed them before that?
Best Regards,
Andrew Trefethen
We feed all the fish the same 1/8″ pelleted floating Rangen catfish food throughout their life cycles, from when they are a quarter of an inch long to when they weigh 9 pounds. It’s not necessary to buy smaller food, bigger food, etc, as it all costs the same per pound, and having different sizes gives you more bins and more “stuff” to keep track of, and more food that can go bad and be wasted. The size of the food is not a problem for the fish: the quarter-inch fish surround the pellets and nibble away at them as they get soft in the water; when they get bigger, they just inhale them.
We have ONE HUGE fish that has developed a unique feeding technique: while the others swim around, bumping each other in their attempts to get at the floating food, he simply “tanks up”.
First, he finds a big patch of floating food on the surface, then positions himself vertically just beneath it. He comes straight up, opens his vacuum cleaner mouth, and sucks in a big patch of food; then lets himself sink just a couple inches below the surface while he pumps the food down the tube. Because he’s directly under the floating food patch, the other fish can’t get to it without bumping into him, so they avoid him; the patch is all his. He comes up again and again, getting a bucketload each time until he’s done, then sinks out of sight. The bottom of the tank is the safest place to be for fish that want to get BIG.
Take note, all you fish who want to get BIG!
Aloha, Tim………..
as of yet I have not found where you mention getting the solids out of the troughs,
my ammonia and nitrate levels are good, but, there is a load of solids in the first 8-12′ that I have been manually removing.
Is this common and no problem, if I do not remove them,
I am researching the manual for tips, what section shall I look for help
thanks
Hi Max,
Have a few questions for you- How much is a “load” of solids? Is it like 1 inch deep or 6 inches deep? What do your roots look like- are they bright white and clean or covered in yuck? What do the solids smell like when you scoop them out? Does it have a foul odor (like its rotting) or does it smell like wet grass? A foul odor indicates there is something wrong but since you said it is only in the first 8-12 feet of your raft I suspect it its excess coir coming out of your seedling net pots as the roots get bigger and push some of the coir out. If you see a change in your ammonia levels make sure to scoop out a handful of the crud and check it for odor- If excess fish food is somehow getting into your troughs it will rot causing the crud to smell bad and your ammonia levels to rise just like a dead fish would. I have a layer of crud at the bottom of my troughs and it’s not a big deal, I do not clean it out- it is not hurting anything by being there, it is giving the bacteria more surface space and my mosquito fish somewhere to hide. Dust, dirt, coir and random pebbles make their way into my troughs too. I will try and find the section where they talk about this topic and post it a little later today for you.
-Jessica
Tim, Jess, Susanne and anyone else out there following this thread,
the system is 30 months old
the water quality is the same as it has been since the system settled down after the first six weeks after startup… Ph-6.25, Amonia1, nitrites 0, TDS 825, DO 5-9
the crud for a lack of a technical term does not smell, the crud is not coir, at first there was a noticeable amount of coir, and we tried to remove it and it just went through the net and would not come out, the crud right now looks like a cloud and does come out with the same 5″ fish net
every week for the past ten months I remove between 2-5 gallons. the plant roots are white in this section, but farther on down the line where there is no crud, it varies, some are pearly white some are covered in slime, the crud does not seem to effect the growth, this section is where the “55s” are, roots are short, plants are small, the crud floats, the crud piles up at the bottom , the crud, moves about as I move and replace the rafts, the crud sticks to the bottom of the rafts, the crud does not disintegrate when put on and around plants in dirt inside or out
the crud gets hard, the crud sheds water when it’s dry around plants in the dirt, the crud doesn’t seem to bother the fish at all, seems not to bother you, the crud does seem to bother the 20 or so other people I have talked with about it, the fish consume all of the food I feed them, there is a natural air stream barrier which keeps the food swirling in on place until it is gone, there seems to be 2-3 quarts of tank water on the floor, just before and after feeding
time, there is a feeding frenzy that occurs when “they” see me approach the tank, there is so much excitement, that I believe that some of the fish are killed by the whipping tails and bodies flying above and in the water, if I didn’t have a net on top of the tank, they would be yards away, we have been experimenting collecting the crud in various ways, some good some not as good, the crud seems to be a topic of discussion, on other web sites, crud collection can be expensive, one guy want to see me a stand for $1600 to hold a crud collector which costs half as much, the crud some people say will kill all of my fish and anyone who consumes the food in the system, wife wants all the crud gone anytime she sees it and will help get rid of it and clean it up as it splashes hither and yon.
I believe if it was pink I could sell it, it’s not, it’s brown and tan it swirls, it dissipates when I try to net it, it sticks to the net, gets on my feet, legs shorts, shirt, if it wasn’t in my system we would, be having this idiotic discussion. tomorrow, after I remove some of the greens, and clean the rafts and move seedlings from the seedling trays into the 55s and from the 55s into the thirty twos and when the system is completely asunder the crud will be there swirling and settling and floating, and I will be there trying to get out and into a bucket
did I tell you about the time when a handle on one of my 5 gallon buckets broke under the weight of the crud,
it was about 835 pm, hadn’t had supper yet, not a cool drink in sight, rafts, packages, seedlings every where it was hot, I was tired, it was no fun, fish were splashing and I had just recently fed them and there was crud it was inside
tears swelling in wife’s eyes, the phone rang, someone wanted me to donate my car
it was a recording, I wondered how old the bucket was, I wondered when the next strap would break
there was more crud
I had yet to hear about the $1600 crud removrer tank stand
I wondered why
I am still wondering about the crud
during a phone call to another state more than 2 years ago, the guy on the other end of the call asked me about the crud, I said that I didn’t have any… he laughed
yesterday I purchased some low tech crud removal gear, wife sneered at me, she had already kit bashed some parts from the basement and garage, and had a fine homemade crud removal system, two hours later it was lying in a pile at the bottom of the trough
tomorrow I’ll slap a bit of crud on to the parts and try to see if we can put it together a bit
more firmly
Aloha All
This is a VERY belated answer to Max’s original question about Crud. I dropped the ball; wrote it back in September, but didn’t post it til now. I’m putting the link in to the document, because it would be two pages if I posted it into a comment. It’s called: “Cleaning Your System”. Here’s the link: http://old.friendlyaquaponics.com/docs/Cleaning%20Your%20System.pdf ; just click on it and you’ll open up the Document That Explains Aquaponic Crud.
Let me know if you have any questions about it, please.
With Warm Aloha, Tim……….