Prototype Aquaponics Project (Charity Chapel) Update

The project still continues and the system is operating as designed.

The vegetables are growing tolerably well though it is obvious that some vegetables grow better in the aquaponic environment than others. To date our green beans were very productive until the ants started "aphid ranching" on them. We harvested about 412 green beans from only 14 plants. Cucumbers also seem to like the watery environment. The vines are thriving and the blooms are many, and we have harvest 19 cucumbers from just two plants. I have planted two more cucumber vines in another grow bin. I have also planted some cantaloupes in two bins and though it is a little late in the season for planting it will be interesting to see their development.

The corn also seems to be growing well as a plant however I'm not sure I like the look of the ears, they seem thin but its still early and they may fatten up. Because of its size I'm not sure corn is the best thing to grow in our bins though perhaps special low bins could be used for this.

Plants that have grown and produced but have not seemed healthy or have not produced much edible have been the squash. Between the yellow squash and the Zucchini squash the Zucchini has done the best. Both squashes have produced 2-3 squash each however the Zucchini plants have grown and looked the best. Currently there are about four 3" squash on the plants.

Both our Bell and Jalapeno peppers have grown tolerably well, and have produced fruit though they tend to be small and frequently fall off the plant. Currently there are several Jalapeno peppers, and there are about six Bells growing on each of the three plants.

The plants that seems to have struggled from the start are the tomatoes. They are stunted and until recently they were quite lite (yellowish) green. We suspect a nutrient deficiency-maybe iron. I stuck two nails per plant at the base of the plants in one bin to see if the iron oxide produced as they rust will help though one of our members has said that there are several states of iron and only one can be absorbed by plants. I have hopes that the grow bin environment will produce the correct type of iron. I am watching new growth to see if I see any color change. We are also increasing the amount of fish food entering the system so this may help.

A problem I think we will encounter though is that when the average night time temps reach the mid to upper 70s tomatoe fruit won't set so it might be difficult to judge tomatoes this season. Because of the above described issues only about three fruit set so this may be all we get this season, unless we leave the plants until the temperatures cool, though then we may encounter other issues- position of the Sun.

We harvested the five large Channel cats we were using to start our system and replaced them with 176 Channel catfish fingerlings. We actually purchased 200 but some died during transport while a few others died of shock though I imagine that the deaths of many of the later were initially due to problems during transport. Three of the 5 larger fish were egg carrying females which is encouraging to our future breeding program.

Though our tank has kept relatively clean we are seeing some slight piling of solids in one area. One answer to this might be the addition of 1-2 small Carp. They will need to be big enough to not be eaten by the cats, but not big enough to bully them for food. I researched Carp and found that they had inherited a bad reputation and are eaten as a delicacy in several Asian and European countries. On our list of fish to raise we may also consider Carp for our US sites.

One of the challenges we are finding is the high temperatures. We have high temps in the 90s and I suspect our only saving grace is that the temp is not consistently in the 90s in a 24 hour period. So far no massive fish kill so I guess we are holding our own. I suspect however that should we lose power for any amount of time the oxygen will be depleted relatively fast.

The system continues to work tolerably well with little maintenance. One problem we have encountered is that of grow bin L-3 not triggering properly. The larger effect is that it causes the water to overflow the bin until the sump is empty, the pump shuts off, then the tank drains to the bottom of the Supply inlet valve so the system is off. Oddly enough ion the three times this has happened it has always occurred in the late afternoon. I say this because I've arrived and found the water still trickling out of the supply valves. Fortunately for us the Chlorine levels in this part of the city are very low during this part of the day and we have successfully added water straight to the sump and thereby bringing it back online quickly. However this is a good reason to proceed with our water catchment system, and to ensure something like this is part of each system we build.

We do have a question about the solids accumulation in the grow bins where the supply dumps into the grow bin. We have added, and will be adding more worms. They seem to move quickly into the gravel but I'm not sure if they are staying in there after the sun sets. I did find a live worm in a bin as I was digging around so perhaps they are staying. I am preparing to dunp about 50 worms per bin to see if how that works, if there is not a notable change we may begin filtering solids at the supply of each bin.

We are intending to grow worms in bins to use as fish food eventually. We have a small colony crowing in a plastic storage bin under on of the grow bins and they seem to be fairly happy. We might consider other insect larva also. I have heard that soldier fly larva is fairly easy to grow.

Thats the full report as of today. Be blessed!