Backyard Aquaponics
A place to discuss aquaponics

Hi, i'm quite new to aquaponics. I accidentally view some videos in youtube regarding this and it makes me very insterested. I had been watching a lot of youtube videos and reading a lot of articles after my interest had been called.

So i decided to design my own system and wanted to implement it after hearing some of your comments and suggections regarding my design.

Please do comment about it. I attached the file for my design. I know many experience aquaponics enthusiast is here and i think they are very knowlegeable with this so i wanted to have opinions from them. I don't really care about how big or small my design is, i just wanted to know if my system will work.

Thank you very much for your help.

Instead of gravel bed for your bio filter, I would use a drum for a radial flow or static upflow filter and use the grow bed as another raft to save space.

Hi Gurkan, thank you for your reply. I was thinking of having gravel growbed because i think the earthworms and other bacterias can help break down the solids from my fish tank. Also, that gravel bed, i will put plants like tomatoes, garlic or onions.

Anyway, what is the advantage of having a bio filter over my gravel bed? I want to know aside from saving space?

as a beginner it wont make much difference - nothing wrong with using media beds, lot of people do it.

The potential problem with your sketch is that you need adequate media or filtering of some form to convert the waste and ammonia. Depending on your fish type and number the fish you may need more media and/or filtering. One option is to make the media bed deeper to get a bit more volume.

But for a new person starting out you should probably just have a few fish and a media bed to start with.
You can easily modify it later and expand. Most people do.

IMO you don't need filters and drums etc in new starter systems. They come later.
Do a basic system first to learn what works for you.

a good video to look at is the IBCofAquaponics that you can see at the top right of this page.
Otherwise take a look at the FAO Small Scale Aquaponic food production guideline
> http://www.fao.org/3/a-i4021e/i4021e00.pdf (or google for it)
These are good simple place to start. The same method works with any sort of containers and grow beds.
And you can use various things as media.

you may have problems running a siphon into your raft beds, but it may depend on how you set things up.
The other option is simply to not bother with the siphon and run as either timer or constant flood (constant flow to raft beds).

>> I don't really care about how big or small my design is, i just wanted to know if my system will work.

simple answer is it is a basic CHIFT PIST and provided there is enough media volume for the number of fish then it could be made to work. But it may not be an easy system to learn with.

Yeah I think it'll work but would prefer to have more media beds to capture and convert the waste. They are filters so the bigger they are the longer they'll last before a clean out (read - hard work in a few years).

Hello nitesofsorde, I notice you have a 500gph pump pumping the water into a fish tank that then flows into a grow bed with a siphon. You mention that your grow bed is 12" deep but not how long or wide it is!

My grow bed is 1m X1.2m X 25cm deep of water filled with clay balls and has between 4 and 6 litres per minute flowing in and siphons every 20 odd minutes. (I will time them soon and work out the exact litres per minute.) yours has the equivalent of 31 l/min flowing in so it has to be a large bed and siphon. If this is the case then you need consider your fish density or tank size because fish density has a ratio to m2 of grow bed which also has a ratio to flow rates.

It may be an idea to incorporate an overflow pipe in the fish tank and a tap to the grow bed so that you get the correct flow to the grow bed to start and stop the siphon. The overflow could go to the raft beds and the grow bed siphon back to the sump. This way you could have an IBC grow bed of approximately 1m2 and the 2 NFT giving a total of just less than 7m2.

1m2 needs between 60 and 100g per day of fish food (depending on what you grow) which would mean you need between 4 and 7 kg of fish at 1.5% body weight feed rate per m2 so that means between 28 and 49kg of fish. That would mean bigger a fish tank or a smaller m2 of grow area. If you have the raft beds don't forget good aeration and a decent filtration system.


I'm also relatively new to all this and I am only passing on what I have understood to be correct from what I've learned since starting to build my system. I wish you all the best with your build and hope I have the above info correct to enable you to help plan your system. KE

Your design looks good. As dlf said what works for you. My advice is if you have the room ensure you leave enough for expansion. As your knowledge develops you will want to tinker and add to improve your design. If you don't have the room then continue to read and learn to optimism your design prior to construction.
Basically the design will work. However depending on your interest and dedication there are improvements that could be made over time as you learn. Good luck and happy learning.

Sent from my SM-P600 using Tapatalk

Hi thank you all for your inputs. Thank you also darren for linking me to the ebook on which i will try to find the full version of it and have it studied. I will try to adjust my design soon.

Thank you also to Know_Expert for sharing your set-up. I just wanted to know also, how much is the ratio between growbed and fishtank? Is it 1:1? I read some articles that says "0.5kg of fish per 20-26 liters of fish tank." Is it ok to follow? I am planning to raise Tilapia in my fish tank.

Also i am planning not to put drain to my growbed, instead only overflow. Is it also ok? this is to maintain only my desired water inside my growbed.

As for my pump size it is around 500GPH because i am planning to use it for future expansion also. Anyway, the output of that pump can be adjusted as to how much i needed.

Once again, thank you all..

Hi nitesofsorde I don't believe there is a fishtank to grow bed ratio. It's more like a calculation of a few different things. Without trying to over complicate things you need to have a starting point.

Eg you know the grow bed area and what you are growing so you now need to work out how much weight of fish food you need to be converted to nutrients (let's say 60 to 100g per day per m2) SO 4kg of fish would need 60g of food per day feeding at 1.5% of their body weight.

Next you need to find out how much water per kg of fish to keep them healthy and not over densely crowded. (I think you said Tilapia?)

So if you have (for example) 4m2 of grow bed and want to feed 60g fish food per m2 (you may need more for some plants) then that would mean 16kg of fish (4kg per m2).... Now work out your tank size depending on density of fish!

If you wish to feed 100g day per m2 that would mean approx 7kg of fish per m2 (7000g X 1.5% = 105g) so for 4m2 you would need 28kg of fish...... Now work out your fish tank depending on density of fish.

This feed ratio is based on media beds and DWC. I believe it's less for NFT


I hope the above is understandable, it's just to show that it's not an exact ratio and that there are things that make a difference.

You could for example already have a fish tank and now you can calculate your grow bed size depending on how many fish you already have.......

OR for people who already have a small fish tank and large beds...... Just grow less plants! KE

>> I don't believe there is a fishtank to grow bed ratio. It's more like a calculation of a few different things. Without trying to over complicate things you need to have a starting point.

yes and no - most calculations are gross simplifications at best anyway because no matter what is adopted the variables change from system to system. Just because it comes from FAO or UVI doesn't make it any more correct because many of their calculations make assumptions based upon data collected in research and commercial level operations.

Most rules of thumb being bandied around by reliable people are pretty good indicators.
Sadly many other people claim all sorts of things.
A lot also comes down to your volume of tank, shape of the tank and level of filtration/oxygenation/water temperature, and pH (pH + temp + ammonia = a big factor in fish stress and survival) etc etc. Then add type of fish on top of that - many of the numbers don't specifiy which type of fish eg. trout are much more sensitive than tilapia for example.

(a) there are some guidelines in the FAO document if you work through that

(b) searching on here will find it is a very often discussed topic.
some include....
good post by Joel EB here > viewtopic.php?f=8&t=79&hilit=grow+bed+to+fish+ratio
scroll through below it pops up every couple posts mixed in with other stuff
( TCLynx delivers the mass to wet volume rationale here unfortunately amongst other posts).
> viewtopic.php?f=12&t=6646
viewtopic.php?f=1&t=26609&p=528736&hilit=grow+bed+to+fish+ratio#p528736

you can search forum and find lots more.

The real relationship is the number of fish (in weight) to wet media. That is where TCLynx was going.
For new systems you should always go much less (EB notes these are intended to be upper limits *not* ideal beginner levels).

I just read dif_perths post and he's exactly right, it does differ from system to system. I was trying to make it simple but got a bit carried away. Sorry about that.......

Anyway, as I said I would earlier in the thread I have measured the inflow of both my grow beds to be 3.3litres per minute. It took both beds 18 seconds (ish) (17.6 to 18.3 over 5 attempts) to fill a litre container. The start to stop of the siphon in bed one took 5 mins 25 seconds and the start to start took 29 min 25 seconds. I didn't get chance to time the second bed but as the siphons, beds, and flow rates etc are almost identical I'd guess that there's not much in the time difference. It's why I questioned the 500 gph (31 litres per minute) going into a grow bed with a siphon.

Keep us updated and good luck with your AP system. KE

+1 Three troughs,RFS,up flow filters to remove the finer solids,sump at the same height as the troughs,fish tanks higher, pump up to your fish tank, gravity through the filters and then the troughs,they will give you your bio filtration as long as you have aeration through out the troughs.
You could maybe add a bio filter into this just to give you added security and opurtunity to decouple in the future if required,in fact if you build that into the sytem if ever you need to treat either side you can quickly decouple.

Whoops I forgot to add a simple MT tank so on a daily basis you collect your solids from the RFS and add them into the MT,just add aeration to this and it should kick ass,if your adventurous you could plumb it in,so it's just a case of opening taps to move solids from the RFS to the MT and the overflow it into the trough maybe with a 200 micron filter sock on the outlet to prevent anything getting into the troughs.