Backyard Aquaponics
A place to discuss aquaponics

Thanks for letting me join you. Got into a conversation in another forum and hydroponics came up. Never really considered it but after listening to a webinar on the topic I'm tempted.

My first question is notwithstanding "Backyard" in your forum title, can this be done on a small scale indoors with grow lights? In a dozen square feet, more or less?

If so, any suggestions on how best to get started?

Welcome. Hehe yes it often starts right there.

Trying to figure out the minimum scale required to begin. I'm retired and live alone in a small apartment. Virtually no natural sunlight is available. I've seen YouTube posts of systems with a 4' x 4' footprint. Thinking I could afford maybe double that amount of space if necessary. Few of the very small systems I've seen seem to take full advantage of vertical space. I'm thinking of putting the planting beds on steel shelving 48 x 24 x 60 inches with 4 foot 4 lamp florescent fixtures above each bedding shelf. Maybe put the fish aquarium on one of the shelves as well. Each shelf is supposedly rated for 600 pounds. I think this is all workable but having no experience or mentor to rely on, it may be fundamentally flawed for some reason.

1. Is there anything wrong with the basic idea described above?

2. How large would the fish tank need to be to harvest one or two tilapias per week?

Thank you in advance.

Hmm, I'm not a Tilapia grower but someone here may be able to give you an answer, otherwise this site gives you size, age and feed rates for Tilapia https://lakewaytilapia.com/Tilapia-Feeding-Guide.php - your results may vary depending on feed, temp, and a bunch of other conditions.

Tank size is not the only thing to think about, you should be asking yourself if you have enough filtration to grow the number of fish you want to grow. Without enough filtration the fish won't survive to eating size. As you get a bit further along this will be easier to answer. The filtration can come from the grow beds or from some other type of filter. One or two fish a week might be asking too much from grow beds for a system in the footprint you're after but I could be wrong . Just a rough and dirty estimate -

A nearly 4 x 4 x 1ft grow bed (IBC grow bed size roughly) would provide enough filtration for you to raise about 12 Tilapia to eating size (going from memory here) based on the information in the IBC of Aquaponics - http://ibcofaquaponics.com/ - I think that only takes about 6 months and you could do it twice a year so you're pretty close.


I like the idea of going vertical but I'm not sure of your spacing with 60 inches of shelf height, multiple shelves and a tank - keeping in mind that grow beds which provide filtration also need enough volume. You might manage one or two shelves but that's about it and I think you'll still need to watch plant height very carefully.

Thank you, Scotty. I couldn't do this without you. So it seems like there are no fatal flaws so far.

By the way, the height of those shelves is 72 inches, not 60 as I mistakenly wrote earlier and could probably have two of them. So if the first rack of shelves held a fish tank and two 2 x 4 foot grow beds, the second rack might have three at least. Potentially 60 square feet of grow bed. More than enough to supply all the basil and lettuce I can eat. Will have to find other low growing edible plants that like being rooted in fish water.

Was looking at sources and costs of baby fish. More expensive than I would have guessed. At such a small scale, the commonplace 20 fish minimum purchase seems less than ideal. If the system is stable and you eat one fish per week, ideally you would add one fish per week to the population. Assuming for simplicity sake that it takes 6 months (26 weeks) to raise tilapia to eating size then you would have 26 fish at a time and each one would be smaller than his next older brother. The progressively smaller size of each fish reducing filtration demand. But the Petco on the corner doesn't list tilapia or any other edible fish on their website.

1. Is it possible to buy fry or fingerlings suitable for eventual harvest one at a time? I'm in a medium size city, Memphis Tennessee.

2. Given my space constraints, is it practical to breed my own fish?

3. I know I need a fish tank and growing beds. When and why is a sump necessary?

Thanks again, for your time and patience.

Contrary to the popular bromide, there are stupid questions. After some more reading, I realize that I asked at least one in the preceding post. I'm learning as fast as I can.

Pretty tough to buy anything but pet store fish one at a time. There may be some alternatives to Tilapia but they probably won't grow as fast. I know I've seen pangasius catfish at petco (these get large fast). Oscars would be another possibility although they're pretty aggressive. I think some of the larger Gouramis are another one that's edible (not absolutely certain about this one though)

You might be able to breed tilapia but you'd probably need another tank. They are about the only food fish you'd stand a chance with.

If your grow beds are lower than your fish tank then you need a sump. If the fluctuations in the fish tank would be too great for the way you want to run the system then you'd probably want a sump. It's stressful to the fish if you pump out most of their water in something like a siphon system or timed flood and drain.

To get my feet wet, I've ordered a 20-gallon aquarium and a two foot, four lamp fluorescent fixture. I use three-foot shelf racks like the four-foot ones described earlier in my kitchen pantry, so will set up a very small system on those to get some of the dumber mistakes out of the way before taking the next step.

Next weekend I should be building a 2' x 1.5' grow bed and buying a couple gold fish to soon be replaced by 10 fingerlings from Lakeside Tilapia. I don't know how long it will take the tilapia to outgrow the 20 gal. tank. I'll call Lakeside Monday and ask them.

So I guess I'm committed to this. Hope you'll be around to answer more questions later. Thanks again for your help so far.

I talked to the fish guy at Lakeway (not Likeside). He says that my 10 fingerlings will be a little stunted in the 20-gallon tank but should end up ok if I get them into larger quarters in about 3 months. At that point, they should be about 6 inches and 3 or 4 ounces.

Looking for something to build the grow box out of and looking at an 18 x 26 x 9-inch white food storage box. Starting to think that the shelving idea isn't so hot after all.

Looking at expandable clay pebbles for growing media. Some of the systems I see have a layer of larger rocks or pebbles on the very bottom. When and why is that bottom rock layer needed?

I think it's mostly to save money, the expanded clay pebbles can be pretty expensive. I used a combination of scoria and expanded clay but would have preferred just the expanded clay. Unless you're pretty careful the layers will wind up mixed together.

Can't believe it's only been a little over a week since I got this hair-brained idea. Got a bunch of stuff and more is being shipped. Decided on two food storage boxes, 26 x 18 x 9 inches to use as grow beds and assumed I would use continuous flow. So I'm reading that maybe the stand pipe height ought to be a little lower in a continuous flow bed than in a flood and drain in order to allow the uppermost roots continuous exposure to air. Does this sound right?

Getting the impression that some plants like basil and lettuce do as well or better in continuous flow compared to flood and drain. Other plants like tomatoes do better in flood and drain. Does lettuce really prefer continuous flow or is it that it just tolerates the sub-optimum conditions better than some other plants? If the latter, then it seems better to make both beds f&d. If the former, then one cf and the other f&d?

In order to give the false impression that there is any real clarity to my thinking at the moment, I put into bold what seems to be the two most pertinent questions but I am painfully aware that I might not know enough to know what to ask. Feel free to answer one or both of my questions and/or offer any corrections or advice you think would be helpful.

None of the pipes within the grow bed should be permanently attached - you want to be able to remove them. This will allow you to change the height of your standpipe so that you can adjust it to change the water level to whatever you want. The main thing is you don't want the surface of the media to be damp and you want the roots to be able to reach water. You also have to remember that the dampened grow bed media is what filters the ammonia and nitrites out of the water for the fish so you don't want to lower the water level very much unless you have plenty of filtration.

You can easily build the system so that you can switch back and forth between Constant Flood and Flood and Drain using siphons. You'll need to size the sump or fish tank large enough to handle the water level fluctuations of a flood and drain system (without stressing the fish). You'll need to make a bell siphon to go over the standpipe in the grow bed. You'll need to drill a small 1/8th inch weep hole near one end of the standpipe (so that the grow bed can drain for the Flood and Drain setup if the power goes out).

When you want to switch from Constant Flood to Flood and Drain with siphons all you do is flip the standpipe so the end with the weep hole is down and plop the bell siphon over the top of the standpipe (usually the standpipe is within a media guard so the siphon has to fit inside this). As the bed fills, the siphon will kick in and you're off to the races. You'll probably have to remove some water before you do that or the tank getting the water from the grow bed will overflow (this should be the sump or the fish tank that you had to size up for the flood and drain setup).

I started out using siphons and have been using Constant Flood for years. I had good luck with lettuce in both types of systems. Every system is a bit different though.

So if it is constant flood, do you want the standpipe lower to permanently expose more of the roots to air than would be exposed at the peak flood point in a flood and drain system?

I've kept mine at about the same level as the maximum flood level I used when I was running flood and drain (water level around 2 inches below the surface - but make sure the surface stays dry or algae and moss will grow where the sun hits the damp media). There may be some benefit to lowering it a bit but I've never needed to. You might be able to alter the oxygen levels, temperature fluctuation and evaporation so it's worth playing with. I sometimes raise the level and then lower it when I'm going to toss some seeds in the bed. It helps them stick just above the water line. I've also lowered the water level for mature plants but didn't really notice any difference in growth so I stuck with what I had.

Set this project aside for a while but haven't forgotten about it. Have had water in the aquarium for nearly three months; no fish yet though. Been dithering over bell siphons but ready to go ahead with it. Question about dechlorination. Memphis Light Gas & Water website,http://www.mlgw.com/images/content/files/pdf/WaterQualityReport2016.pdf says in part:

I can't find any mention of chloramine.

1. Do you think bringing tap water to a sustained full boil for 20 minutes is adequate to ensure safe water for an aquaponic system?
2. Do you think municipal water systems are generally trustworthy in this regard?

Getting ready to wash the Hydroton going into the grow bed.
Thank you in advance for your consideration.