There is a language somewhere, possibly a now dead language, in which the word aquaponics translates to “anything that can go awry, will indeed do so at the earliest opportunity”. Here is a brief description of our sorted issues and how we’ve addressed them.
image1) The system drains too fast or too slowly. I’ve gone into the backyard to see hydroton floating around in the grow bed and the fish tank water half gone. On the flip side, we’ve also had massive seedling die offs due to lack of water. Sometimes the grow bed would be dry AND the fish tank would be half empty. Huh? We’d fiddle with the pump rate. Or the drain holes. And just when everything seemed to be okay….hydroton pebbles and seedlings would float by in the overflowing grow bed. Sisyphus meet Aquaponics. We finally solved this issue with a timer. The timer turns the pump on and off every 15 minutes. Twice daily, the pump is off for 45 minutes so the growbed can completely drain and we can check the fish tank level. I love this timer and have completely forgiven it the incident where I was severely shocked when trying to plug in one of the pumps. Water and electricity, always a good combination. The drawback to this solution is that on and off over and over is hard on the pump. After a year and a half, we had to replace the pump. Our next system will be a bell siphon.
20130603-184405.jpg2) Evaporation. As we are in southern California, our water evaporates fairly quickly and needs to be topped off every week. During the latter part of August, we would top off the tank twice a week. We tried using our two pitcher style water filters, but adding 10 gallons or so from water pitchers is crazily time consuming. We finally purchased an RV water filter for 18 dollars from Amazon and attached it directly to our garden hose. We test this water to make sure its lacking in chlorine and just add water directly to the system from the filtered hose water.
3) The water is incredibly dirty. We started out with a 100 gallon tank and 30 fish. The water stayed pretty clear for quite some time and then, after a number of weeks and in a matter of a few days, got so dirty we could not see through it. Clearly, we needed some back up water filtration. We set up a pond pump with a biofilter. After two days, the water was only marginally better. I’m sure the biofilter needed more time to get established, but the water was just too nasty. We had a number of plants, slow growing to be sure, but those plants should be using all that good fertilizer, right? We pulled the filter out and put the pump back in and ran the second line into the grow bed. Overnight, the water was clear again. This second pump was small, however, so after a couple of weeks, the water began to get dirty again. We bought the biggest pond pump Sunland makes. We run the large pump and our original pump full tilt. On and off every 15 minutes. Ahhh, nice clear water with a pH of around 7.2.20130603-184618.jpg
We later determined the culprit to be not the pump, but the lines. They were clogged with fish goo. Hmm. Well, the chopstick worked for the drain holes so I used a long bamboo stick to muck out the line. Now, we regularly clean the pumps (two small pumps are fine) AND the lines and the water stays in fairly good condition.
4) Chickens in the grow bed. This next issue was utterly vexing. The stupid chickens got into the grow bed. We saw two options. Option 1: Chicken Pot Pie. Yummy. Or, because they lay our eggs, Option 2: Chicken wire around the entire grow bed. This worked for all sides except the side up against the table. We found some nice clamps to affix the chicken wire. Be careful of those things, though. They’ll grab your hair and affix you to the side of the aquaponics growbed. It’s not pleasant. The new chicken wire worked for nearly two months. Then, the maybe-not-so-stupid chickens were hopping onto the table and climbing over the chicken wire to gain access to the grow bed. Engage chicken consumption of our seedlings. Back to Option 1? No, no. We put a net up that runs from the ceiling of the porch to the grow bed. It doesn’t look nearly as tacky as it sounds, really. Maybe some Japanese glass float lanterns would help…
Our chickens now stay in their coop area most of the time and when free ranging, tend to leave the aquaponics system alone. Perhaps they’ve forgotten about it…
image5) Our plants were growing veeerrryyy slowly. Also, the tomato plants had a fair number of brown leaves and a lot of seedlings never got over an inch or so tall. This turned out to primarily be a function of the small size of the fingerlings and the low amounts of fish goo. We just rode it out. As the fish grew, this became less of an issue. Secondly, although the location of the system is aesthetically pleasing, during the winter, this bed receives almost no sunlight. We installed a small grow light, which did help. We are planning to put a larger one in, however, as everything growing in that bed slows down so much during the winter months.
image6) Caterpillars are rampant. I’ve been pulling them off and feeding them to the chickens when I find them, but they are proving to be too wily for me. We tried sprinkling cedar chips into the bed. A few sources claim caterpillars do not care for the smell of cedar and that using cedar for mulch will chase those nasty buggers off. Cedar seemed safe enough for the fish. Note to self: caterpillars in our yard have utterly lost their sense of smell. The cedar did not affect the fish but, alas, it also did not affect the caterpillars. The upside? The backyard, despite the presence of the utterly potpieable chickens, smells fantastic! Several sources claim that BT spray is safe for aquaponics systems. We are not crazy about such tactics, but we are also not running a bed and breakfast for cabbage loopers. The BT did seem to work on the caterpillars, but it put the fish off their feed for a few days. The fish seemed fine by the end of the week. Now, we only employ the use of BT sparingly and when our seedlings are disappearing rapidly before our eyes.
7) Dead fish.    One morning, we found three dead fish floating in our tank.  We checked the pH, the nitrates, and it was summer, so the temperature of the water was fine.  They were our three largest fish!  After doing research, we found information that indicated higher temperatures, such as those we’d been having, combined with algae in the water results in a lower amount of dissolved oxygen in the water for the fish.  This lowered oxygen is harder on the largest fish.  They had not been gasping at the surface, but evidently, sometimes, they will not do this.  DO meters are quite pricey, so, we added a small airstone (6 bucks for the airstone and we already had the pump and hose) just to up the DO in the water.  We lost a couple more one night when this little pump died. When we replaced this pump, we improved on this set up with a slightly larger pump that runs two airstones at once. During the winter months, we turn the circulating pumps off to keep the water warmer at night and the airstones help keep the water oxygenated at night.  
8)  No water.  This issue was radically different from the above issue, in that, I could see where the water was.  It was almost ALL in the growbed or on the floor of the greenhouse.  The poor breeders were on their sides gasping for air in two inches of water.  I was horrified.  I immediately switched the pump off and unplugged the hole which has all completely plugged overnight.  To avoid this issue in the future, we acquired bathtub hanging whatsits to set the pump in.  If the water goes below the pump, the pump may burn out, but the fish will be fine.  A satisfactory trade, I say.
  1. Madmike23 says:

    Great resource! Thanks for the info! Do you recommend the use worms instead of some type of filter?

  2. Madmike23 says:

    Great information, an excellent resource! Thanks! Do you recommend worms instead of a filter?

    • ocmetrofarm says:

      In our aquaponics (aquaculture+hydroponics) setup it is the plant roots and worms that provide the water filtration for the fish, and the fish in turn which provide fertilizer for the plants. In standard aquaculture (fish, no plants) a man-made filter is used, and in standard hydroponics (plants, no fish) fertilizer from outside the system is added periodically.

  3. Mike Oen says:

    Awesome information, and excellent resource. Thank you. Do you recommend worms instead of a filter?

    • ocmetrofarm says:

      Good question! Certainly. We presently do not use any manufactured filters in the system itself. The only filter involved is the RV water filter we attach to the garden hose when adding new water to the system. Each time that the tank water has become cloudy, it has been corrected by flushing the pumps and pump lines, cleaning the bed-to-tank drain holes, and otherwise increasing the rate of water ‘throughput’ from tank to bed to tank. Worms are excellent for improving the bed’s function as a biofilter, and improve the growing environment for the plants in the bed. And if the happen to fall through the drain … surprise fishsnacks!

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