Backyard Aquaponics
A place to discuss aquaponics

Hello everyone,

I just recently introduced myself as new member to your forum. I am a hobby aquarist since a very long time and I've had all sorts of ornamental fish and shrimp, of which I bred a few successfully.
I am back in Austria since one year and more than half a year ago I couldn't resist the urge to get an aquarium again. This time though I wanted to try out something new with new fish, but also go further and start with aquaponics.

I have researched a lot before getting started, especially because I live in a flat and therefore I do not have a lot of space and light to grow my own vegetables and herbs. To make it even more difficult I wanted to try out something completely different and go with Malawi Cichlids, which require a higher PH than everyone would deem good for aquaponics because of the nutrient availability for the plants.

I bought a standard plant growing module for walls and changed it to my liking to be able to grow vertically on a small space of one of my walls.
The module itself is working now in a sort DWC/NFT mixture kind of way, so no substrate, but I designed the backflow to the aquarium in a way that the water gets aerated well enough so the roots of the plants get enough oxygen.
It is a standard 200L aquarium with 15 young but colorful Malawi Cichlids and I am using an external Eheim Filter, which is able to completely cycle the entire watervolume between 2 to 3 times per hour if I turn the pump up to the maximum level. For the lighting I chose to use RGB LED Strips for a total of 70W.

Concerning the plants I am currently trying out the vegetables and herbs which are kind of "easier" to start from what I have gathered in knowledge:
-2 different types of basil (genovese and ocimum)
-2 different types of lactuca sativa (seurat and descartes)
-lollo rossa
-komatsuma green boy
-oregano
-romanesque cauliflower (just for the fun of it to see if it would actually work because I read somewhere that it does require a water with a little bit a higher PH although definetely not as much as what the system is running on)
-peppermint
-and last but not least lemon balm

I am constantly monitoring the water parameters and so far I observed that potassium got sucked out quite quickly by the plants. I didn't put in any iron fertilizer because I would much rather want to try and do without or get in some iron through fish food. There seems to be enough nitrates in the system since I can still measure it if I don't change a part of the water (maybe the test kit is not accurate enough). I am not measuring any ammonia or nitrites so it seems the biofilter itself is doing its job as it should.

I am quite aware of the fact that the way I set up my AP system is not the optimal way for growing but since I wanted to try out this kind of ornamental fish I just wanted to see if I can also somehow manage to make an AP system out of it in my flat (on the positive side I am not bound to weather or seasonal conditions and temperature changes at all). I did notice some deficiencies in 2 or 3 plants (lollo rossa, lemon balm) but I am not sure if this is due to the lack of iron, the low level of potassium, or the low level of phosphates.

Unfortunately, what I am doing here in terms of size is no where near to the nice and huge things I have already seen here but I still want to have a little vertical green garden in my room from which I am able to eat something off of .

Most importantly I will have to pinpoint the reason(s) for the deficiency or deficiencies that I can see in some plants. Anyway I hope that I will be able to find out a lot more things with this system, which I will be happy to share with you should anyone want to know if it is possible to grow something in these unfavorable conditions .

Regards,
Alex

Hello Penzi! I can't really help answer anything as I'm still piecing together my first system but just wanted to chime in as I come from being a hobby aquarist - share the same name - and looking to build a small system like yourself with ornamental fish! I haven't seen a lot of threads building systems like this so I'm very much looking forward to updates on yours as well as some pictures

Which Malawi Cichlids are you using in your system? What pH are you running at?

Cheers!
Alex

Hi!

I'm happy to see that approach aquaponics from the same angle ! I would've also liked to build a bigger system with Tilapias but for many reasons I am not able to unfortunately (statics - I live in a 100 year old building, available space, availability of Tilapias in Austria) but since I rarely came across small, controlled systems in apartments using ornamental fish (other than goldfish) I thought I'd give it a try. A friend of mine is also installing a system - the same system basically but he is using South American Cichlids which require a lower PH. The rationale behind our little project is that I can have a higher fish density with Malawi Cichlids and the ammonia -> nitrate conversion works better but all this it a the cost of running the risk of other nutrients not being available in a proper amount as a result from the higher PH whereas my friend has a better PH value (as required for south american fish) for the nutrient availability for plants but a lower fish density and therefore a lower amount of nitrates being produced in the system. So we will be able to make comparisons in the future with our two systems.
The benefit of using LEDs is that I can change the color of the light via a controller that I have installed thus allowing me to also tweak and try out different lighting recipes and monitor the effect on plant growth (the only little drawback is the 1:1 R:B ratio I have in the system but that could be changed easily). Furthermore, being able to turn off the green LEDs saves more than a third of energy, both cost and heat (through which I can prevent the vegetables from flowering because of the reduced temperature). Furthermore, I should be able in the future to simulate the daylight cycle concerning light spectra, but currently the LEDs are just running constantly for 16 hours and then they shut off automatically.
I currently have a 200 L standard sized aquarium and 15 Malawi Cichlids swimming around happily. 5 Labidochromis caeruleus yellow, 5 pseudotropheus elongatus mpanga, and 5 Labidochromis hongi red. All of them go well together, especially the yellow labs fit in everywhere. The Labidochromis hongi and Pseudotropheus elongata are the more dominant species in the tank but they all seem very happy overall.
The PH value in the system is at a constant 8.1 or 8.2 but there are enough nitrates for my set up it seems. I am still constantly trying to find nutrient uptake values of vegetables to be able to properly set up the system and have a balance since I can estimate how much N is being introduced into the system through the fish food in relation to the weight of my fish. Finding out plant nutrient uptake is unfortunately very difficult and I have not yet been that successful with it since I can't find many numbers (if anyone has an input to this I would be very glad and thankful) so I just bought a book for hydroponic vegetable production in the hopes that I will get some information there.
Since a smaller system is more unstable and Malawi Cichlids require a bit more attention in terms of water parameters I am monitoring everything a lot now until I can say with a certain amount of security that it works properly and reduce my monitoring efforts.
Concerning the lacking nutrients for the plants I recently came across fish food where the trace elements are also listed and I hope that some of the trace elements will end up in the water. I guess from what I've seen and read so far iron does not need to be higher than 10 mg/l for the plants in the system, but potassium should be a bit higher. Once I got the system to run potassium got drained to half of its initial value. Phosphates I am also able to measure but that value has not been reduced yet by the plants drawing nutrients from the system.
Still I would like to be able to quantify how much an additional plant will draw from the system so I know if I have to make my wall in my room greener .

Can you tell me something about your plans? What aquariumsize have you chosen? What type of fish will you be aiming for? What vegetables to you want to grow? How will you take care of lighting?

Anyway I am glad to hear that you are like-minded and I will give updates to my system (pictures I will post later today). Unfortunately I assume we live in very different timezones so it will always take a little while for me to respond .

Regards

Will be curious to see how both you and your friends systems compare based on the differences in pH and fish tank stocking levels.

I keep going back and forth on aquarium sizes due to limited space where I want this setup (in the kitchen). Likely a 33 gallon long or a 40 gallon breeder. I have room for a larger tank (75 gallon) but not more growbed space since I'm using 55 gallon barrels cut in half as the grow bed. As of now it's likely I'll go with a simple flood and drain or continuous flow setup though, ideally I'll like to do a CHIFT PIST setup. I finally found a source for the barrels so little by little we're getting there

The fish I'm planning to use if anything under the 75 gallon will likely be livebearers such as platy's or other south america community fish that I can keep around 7 pH. I was thinking of doing yellow labs as well if i do end up going with the 75 gallon but my concern is having enough growbed space to keep up with the filtration requirements and then obviously bumping up the pH to around 7.8 ish.

As for vegetables I'm planning to start with leafy greens, lettuce, green onions, chives, celery, kale, bok choy. If things go well then I'll try and do some peppers

Lighting I'll likely go T5 unless I can find some cost effective and solid set of LED lights.

Hey there!

Sorry for my late response but work has been quite heavy these last weeks. Unfortunately it took a little while to get the second aquaponic system with the south american fish going for the comparison but it should be up and running anytime soon now.
So far I can see that, with my system, it is a little bit difficult to grow lemon balm, the romanesque broccoli, and the oregano (some show a chlorosis, others have burnt leaftips) which I would accredit now to the lack of iron and/or potassium. After having put my plants into the NFT part of the aquaponics system the potassium got drained immediately and there's no iron in the system since I didn't add any (also, once I add iron, it will be interesting to see how much of it the plants can take up at this high level of PH). But the rest seems to be doing fine and is growing. I assume that everything would grow much quicker if I added iron and potassium but I want to see how everything evolves without me having to add anything on a permanent basis. However, I am doing constant water testing to see how the plants affect the water quality and how they take up the available nutrients and of course also to monitor the well being of the fish. So far I can say that the fish are doing fine in this constellation. I would have assumed that, over time, the PH value of my AP system will drop as the plants take out the nitrogen in the system but it seems so far that the PH has even risen a bit. Altogether though, it is constant and very good for the fish at least. I have already built an AP system for a friend, also a CHIFT PIST system with Growbed and Tilapias and the plants in there are doing very fine. In that system I was also able to witness over time a drop in the PH level from 8 to around 7.2, which seemed to have benefitted the plants quite a bit.
So I am assuming you are going to work with an autosiphon? Concerning the noise levels I have to say I like the constant water splashing in my room as it is very calming (but not too loud) but I know from the first CHIFT PIST system I built in the apartment of a friend that the flushing intervals to tend to make a little bit of noise.
75 gallons will give you a nice big space or your fish which should keep them very happy and you have a huge choice of ornamental fish, which is very nice! I guess the idea with livebearers is a very good one since they also reproduce very happily and you can also hold them in higher numbers relative to the size of your fish tank as compared to south american cichlid fish since you also need a large source of "nitrate production".
Also, the choice of vegetables seems very sound and good, for peppers it would be interesting to see how they grow since they do need a little bit more of other nutrients that leafy vegetables need less of.
Concerning the lighting probably to go with standard T5 lighting is the best and cheapest choice for indoors unless you are able to build your own LED lighting solution. I have chosen the latter option but of course it takes some time to build a proper LED lighting system. How far are you with your system now?
Unfortunately I am still not able to find a lot of information on plant nutrient uptake on a daily basis (per plant or per m² of one type of plant). I only found nutrient solution formulas for types of plants but it there is no mention on how much a plant takes up nutrients out of these solutions per day. It is a complex topic but I am trying to find an approximation of how to calculate nutrient uptakes so I know in the future how big I can design my next AP system.

Cheers!