Backyard Aquaponics
A place to discuss aquaponics

Well done CaptKarel. A chop and flip is the best way to start off a system and I'm looking forward to watching the expansions as I'm sure, once started, you'll be forever thinking up new additions and modifications as the bug bites deeper LOL. I understand your frustration with birds destroying everything as quick as you can plant. I have built a netting cage (6 x 10m) to keep them out of my dirt veggie garden, but fortunately they tend to leave my outdoor AP system alone (however this year for the first time I've had a battle with rats which appeared as soon as my neighbour bought chickens).
My indoor AP system is set up in a greenhouse (6 x 4m) and at once stage I even had a rat show up in there (instantly recycled as fertiliser).
Sounds like your temps summer and winter are about 5C below ours so should be able to keep things ticking over all year round. I'm sure you will like your AP veggies....they are sooo tasty.
How good to see your system being set up...the fun begins!

As you all know there is a learning curve and sometimes the lessons could be hard or expensive.

I therefore did a lot of research, including lots of youtube videos. There seems to be a lot of information out there, the trick is to sift the facts and not to get distracted by fancy gizmos. I usually like to keep things simple and easy to fix.

I also spend quite a lot of time reading through this forum trying to learn as much as I can. I must say there is an absolute wealth of information here, please keep it up.


CaptKarel

Herewith is my build below:

I managed to obtain a 1000 L IBC at a good price, it was more or less clean and only had one hole in the top of one corner. The previous owner used it to capture rainwater for his pool.



I the cut the top 300mm of the tank off to form the grow bed, the frame I left intact, I planned to use 4 wood support for the grow bed.


These wooden beams should be more than enough to support a full grow bed.


CaptKarel

I selected a 2400 L/hr submersible pump designed for continued operation, and installed that on 2 bricks.

The bricks will prevent the pump from completely draining the fish tank in case of some failure in the plumbing.



I also fitted a t-piece with a flow regulator valve to return excess water back to the tank, at the same time I fitted a small pipe with an air pickup above the water line to aerate the water, this should provide more or less enough dissolved oxygen in the fish tank water. I might have to add an air pump later.

The pump deliver the fish tank water to a small solids capture tank above the grow bed.

The water then flows up through some shade netting and then by gravity to the grow bed.



The delivery elbow from the pump has a small hole in the top to prevent siphoning of the dirty water from the bottom of the solids trap if the pump is stopped.

The pump pipe is fitted with a quick disconnect to enable me to easily removed the whole thing for cleaning. The shade net will get washed on the lawn and the solids will be deposited in my soil vegetable garden, so no wastage.


CaptKarel

The grow bed had a hole in the corner which I decided to use for my external auto siphon.



A 50 mm PVC pipe across the bottom with slits drains into a t-piece which is part of the siphon. I will have to keep an eye on this pipe as it may clog with roots at some point. I did select a t-pice with an inspection cap and can also completely remove the external siphon to clean the pipe from the outside in such an event.



A 50mm uniseal was used to close the gap between the pipe and the side of the IBC. I was forced to use this existing hole and only slightly enlarged it to fit the seal and pipe.

I very small leak was observed once the grow bed was full of water, but this was fixed using a few wraps of teflon take around the uniseal. If it does leak in the future again it will at least leak back into the fish tank and not to the outside.


CaptKarel

The external auto siphon bell was made up of a 50mm t-piece, 50mm pipe and cap. The stand pipe consists of 20mm and a 20-25mm reducer at the top and bottom. this improved the start reliability of the siphon,however the top must be as level as possible.




The bottom of the standpipe goes through a 25-50mm bush reducer then a 25mm down pipe with elbow return the water to the fish tank.

It was found by experimentation that the gap between the top of the stand pipe and the cap should be as small as possible or not more than the diameter of the standpipe for quick start of the siphon. This keeps the air bubble that must be sucked down as small as possible.



The length of the down pipe and horizontal pipe is found to be optimal for positive stop of the siphon if the length is between 2 to 3 times the length of the stand pipe. If too short there is not enough “suction” to give a positive and reliable stop to the siphon action. That is why I found that I did not need the siphon breaking snorkel pipe.

The advantages of an external siphon is that no planting space is lost in the grow bed, however it being on the outside there is a greater possibility of damage.



Lastly I found that if I want to work on the siphon or need the grow bed drained, I need to wait for the draining cycle to start and then switch off the pump and wait until the grow bed is empty.

the only joints that was glued at the end was the 50mm cap on the bell, the 25mm pipe passing through the 25-50mm bush reducer and the 20-25mm reducer at the top of the bush reducer, the rest are all friction fit and sealed with teflon tape where needed. I also used stainless steel screws on the t-piece connection to the drain pipe.

I found that the fill cycle with my pump setup is about 15 min and the drain cycle just under 5 min. thus I have about 3 to 4 cycles on average per hour.



CaptKarel

The grow bed is filled with some stones bought from the local building material supplier, before buying the load it was tested with white vinegar to verify that it will be stable and does not contain any lime stone or such.

The stones was manually washed and then loaded in the grow bed.



I bought 1/2 a cubic meter of building aggregate which filled my double cab bakkie (ute, pickup, truck) almost to the brim. At the end I used about 1/3 of the load to fill my grow bed.



This was the most physically demanding and lengthy process of the whole build.

I filled the grow bed to just under the top lip to ensure that the top of the stones stay dry when full of water.

I found that I used about 2/3 less water with the stones in the grow bed and the fill and drain times were about a 1/3 of the times without the media.



The top layer stays nice and dry and hopefully no algae will grow on top.


CaptKarel

I wrapped the whole setup with roof insulation and some reed to make it a look a less industrial.



I treated the water to some fish emulsion and ammonia once a day for a week.



Tested for ammonia and it is just under 5 ppm, also looks like some nitrate is present, probably from the fish emulsion.



Planted the first plants, only 3 baby spinach, will monitor how it goes.




CaptKarel

Week three:

The Ammonia still very high but the Nitrite started picking up.



Rest of the parameters looks ok.



Some growth apparent on the plants after one week.



Water temperature on average about 14 to 15 deg C, definitely winter now, air temps so far 4-7 deg early in the mornings, topping at 26 in the day.

We might still have some really cold spells in July, even might get some frost.

Not yet ready to add fish, maybe a month or two still to go.


CaptKarel

Nice job. Cooler temps may cause a longer time period be necessary to cycle the system.

It is now 5 weeks since the system has been put into operation.

The pump is running well and the external auto siphon is working like clockwork. There are no leaks and only water loss seems to be from evaporation. Had to top up the tank with some rain water.

The weekly water tests still indicate high ammonium at about 10 mg/l. The nitrate has decreased a little bit but the nitrite is still on the high side.





The wife added a leek and the spinach is doing well. Of the four that was planted a few weeks ago one seems to be lagging. Maybe the small roots got damaged during the transplant but it seems to slowly recover.









I added a little bit of Iron Chelate last week since some of the leaves showed some yellowing. That seem to show some good results since the yellowing is all gone now.

Overall the systems is doing well, even though we are in the middle of our winter.

The water temperature seems to be vary between 20 to 24 deg C, night and day, even if the air temp drops as low as 5-7 deg celsius. I found that my temp sensor was hanging on the bottom of the tank registered much lower. Now that the sensor is hanging more or less in the bottom third away from the side, the water temp is much more steady.

Maybe in about two to three weeks, if the ammonia drops, I will add the fish. I have already decided to add 10 small koi when the system has fully cycled. I have stopped to add any ammonia or fish emulsion for now.

Comparing the plants in the aquaponic system to plants outside, from the same batch of seedlings, the aquaponic plants are growing more than twice as fast and looks more healthy.

It seems that my PH tester is reading a much higher value than the strip test. Maybe I will have to calibrate it. It also reads slightly high in distilled water. It did indicate correctly about three weeks ago before I topped up the water.

Any advice or comments welcome.


CaptKarel

For the last 5 weeks you've been adding Ammonia to the system everyday or every week?

If it's still reading 10mg/l (Ammonia) it may never cycle,especially with cool water.And if the test kit doesn't read higher than 10,the real number could be a lot higher.
The Ammonia will act as an disinfectant & stall the cycling.

When or if the Ammonia comes down with 10mg/l,the Nitrite will be off the chart.

If you fancy an opinion,I would do a part water exchange to bring the Ammonia down to 2 or 3mg/l & then don't add any more Ammonia or fish emulsion.

Thanks for the advice.

I only added ammonia and fish emulsion twice a week for the first two weeks, then once a week after that. Nothing added after the 4th week. I think I might have added too much fish emulsion, 25ml per dose.

We had a really cold spell during the 3rd and 4th week. The last couple of days were much warmer.

I did add about 100 liters of rain water at the beginning of last week and about 80 liters of tap water. Unfortunately I have no more rain water until it rains again. Still many months to go. Total system volume is about 500 liters.

The tap water did cause a rise in the Calcium hardness, we have very hard water, but not in the general hardness.

I will need to treat the tap water for chloramine and hardness before I do a water change or top up though.

I have read that if you aerate the water for 2 or 3 days it should off-gas most of the chlorine, or use the same chemicals used for aquariums. Not sure which is best yet.


CaptKarel

KH is nothing to worry about unless it's keeping your PH too high (and it is).The rain water will sort that out eventually,then when you have a PH of about 7,just use your tap water to add the Carbonate again & hopefully hold the PH there.
You're very lucky to have high KH & low GH.

You could get a de-Chloarmine & Chlorine (2 in 1) filter,just run your tap water through it & it'll remove both of them and remove heavy metals too.
Yes,Chlorine will gas off.Leave it in the sun & give it a good stir.

Koi will grow to be a big fish one day,10 is a lot.