Backyard Aquaponics
A place to discuss aquaponics

Hi this is the early stages of my very first simple AP system woohoo! I've cut one ibc into what will be a 700lt FT & 230lt GB approx. I'm not sure how to proceed next coz I've been reading about the ratios and it seems you should have 1:1 GB:FT ratio minimum or even 2:1 ideally, mine is way off at 1:3. I want to ideally get maximum fish and veggies possible from my setup and can probly get one more ibc. Does getting this & cutting it into two more 230lt GB's for a 1:1 ratio sound like a good idea? I realise that would be heaps of water out of my FT, is this why some then add a sump? Not sure about flood & drain or constant flow yet does constant flow address the FT water level issue? Sorry bout so many Q's guys the more u learn the more there are, Cheers.

Welcome old muel !

If you haven't already read the IBC of aquaponics.. As a fellow newby I can say it helped heaps..

In regards to your questions.. It appears Flood and drain and Constant flow are very similar in terms of performance and so the choice comes down to personal preference and system design.

Adding the extra IBC to have a 1:1 will definitly help increase the maximum fish stocking level. the key to remember is that GB are your main filter, so if the ratio is not in balance you will need additional filtering.

The sump does help keep water levels more constant in the FT when using a flood and drain setup, but it adds cost and complexity it depends on what direction you wish to go in.

That's my 2c, welcome aboard and best of luck

Hi old muel,

It's not so much a ratio of FT to GB, it's just that the GB's need to be big enough to deal with the fish waste or the fish will poison themselves!

That system will work fine for 10 to 15 fish but if you want higher stocking densities then you will need more GB/plants/bacteria to remove the ammonia the fish produce.

You could just cut the other IBC into 2 GB's and run CF and have the FT full but if the pump ever stopped it would overflow your fish tank, depending on where your system is located that may not be a huge problem

Good luck with it

Cool thanks heaps for the replys, i did read ibc of aquaponics that's where i copied the design for the single ibc setup i was just thinking that's a waste having such a big FT and not being able to have many fish in it because there's only one GB/filter. So I'm gonna add the two more GB/filters so i can stock more fish then i can also grow more stuff aswell. So running CF would keep my FT at a constantly full level - Awesome that's exactly what I wanted to know, because running F&D without a sump would take nearly half out of the FT at a time meaning less fish in there, right? Cheers guys you rock.

You could always run one bed as a siphon flood and drain and the additional beds could be constant flood. What ever seems to work best for you.

Can't get hold of extra growbeds/media (going with clay) so setting it up with one growbed for now, plan to get it cycled and add the other GB's in a little bit. The pump I had laying around is too weak to pump the water directly up so have to have it at an angle & near the top of the FT (900lt/hr pump). should the pump be right at the bottom of the FT to get any solids off the bottom?

head height is measured from the water surface to how ever high you are pumping so it shouldn't matter if it is at an angle or straight up.

However, I wonder about the size tubing. Bigger plumbing can often help you get more flow out of a tiny pump.
So called 1/2" irrigation tubing uses those barb connectors that really restrict flow to more like 3/8" or less and if you simply used some 1/2" PVC you might see a great increase in the flow from that little pump.

Remember than a 900 lt/hr pump will only move that much water at 0 head so if you are pumping up 60 cm that pump is not going to flow nearly so much water per hour. Look for a pump that will move 1000 lt/hr at about 1 meter head and you might have a pump that will suit the system once you add a couple more grow beds.

For now, with your little pump, perhaps upsize the plumbing and if there is a sponge filter in it, take the sponge out and check to make sure if there is any flow control on the pump, that it is set to wide open.

yep cheers TCLynx I havn't used the barbs because of that but the irrigation hose is inside the pump nozzle so I will get thicker hose/pipe and have it over the nozzle instead- should help a bit. There's no sponge & it's wide open, think I'll get a bigger pump though where do you guys position the pump-at the bottor or near the top of FT? Gonna paint it & get clay balls today wonder if any old spray paint will do?

Pump at the bottom, old_muel. That way solids can be pumped to the grow bed.

Yes you want the pump near the bottom but I often have the pump up off the bottom a little bit just to protect in case of major plumbing failure at least you will still have several inches of water left for the fish. You can't really leave the pump near the surface because if you have any water level fluctuation the surface height changes and as water level drops due to evaporation or the plants use the water you don't want your pump running dry because it is hanging at the surface. A bigger pump will also be better able to handle the solids, tiny pumps clog so easy.

Cheers guys I scored a 2100lt/hr pump off a mate & got clay balls today pretty much all sorted now woohoo, got some feeders and a few goldfish in my indoor aquarium waiting to be thrown in to cycle my system, now just gotta source some edible fish. I like the idea of having a reasonably sustainable system by breeding the fish is there any species i could get that would readilly breed? what about tilapia in aus? Also what about redclaw?

Breeding your own fish is kinda over rated. And Tilapia are over rated. And in most of OZ they are not legal anyway. You need quite an extensive operation to really keep up with breeding. You need to keep the water warm to keep the tilapia alive let alone breeding or eating and growing.

I'm in Flordia USA and lots of people around here grow tilapia but even here in our subtropical climate, heating is required during the cold spells just to keep tilapia alive and if you want the tilapia growing at peak or breeding you need the water temp very warm (warmer than the plants like it.) There are other native and local fish I can grow here that grow FAST and get BIG and don't require me to heat the water. Drawback is I do need to get new fish from the fish farm every so often but for me that is rather convenient. We have channel catfish here that can easily reach over 1 kg in less than 12 months in our warm climate. I don't know if OZ has anything quite like that but I would certainly encourage you to use locally available, legal and climate appropriate fish before trying to do tilapia.

Sorry Old-muel... Australian species can be hormone induced to spawn in tanks.... but very, very few of even the most experienced of aquaculturalists have successfully got them to grow to fry... and on to pellet feed...

Tilapia are banned in Australia...

Hey guys how are we it's been a while since i posted just an update and few questions. Got everything running ok although very slow growth on plants and my 7 goldfish, didn't have a test kit while cycling but nowdays ph is 6.8, ammonia .25 and no nitrites or nitrates, not even sure its cycled properly its been 5 months but maybe denser planting and swapping the fish out for perch might help thinking of trying that jus dunno ???, running mains power F&D 15 on, 45 off. Also I've put together a solar setup with 12v pump that works well except wiring up the cycle timer has me stumped i'm hoping someone can help me make sense of the circuit diagram, power in is working but don't know how to connect the load (pump), tried + to NO (normally open) & - to COM (common) but no dice, cheers peoples