Backyard Aquaponics
A place to discuss aquaponics

Gravel is a lot less expensive, but a lot heavier! Your GB and support needs to be able to handle it. I used a mix of mostly gravel and a bit of clay in my first system, and all gravel in my 2nd system.
Water depth should be 30-50mm below the top of the gravel, to avoid unwanted growth of algae, moss etc.
2:1 ratio would be referring to GB:FT volume, but it isn't a hard and fast rule, plenty go with different ratios, it depends a lot on how many fish you have, and other factors. 1:1 has been working perfectly well for me in my small system, and it's closer to 1:2 in my larger system, although I have more veg growing area to add when finances allow.

Ok here is a curve ball i may be going up the wrong creek here but what about a NFT aquaponic system is this even possible? it would most definitely be cheaper and lighter than going clay balls or gravel

If i could go NFT aquaponics where would the good bacteria grow seeing as I'm taking out a huge percentage of the growing medium?

I done some searching and u can in fact use AP in a NFT system, i think i have a idea i would like to try

I need to cut one IBC tank in half so i have two even halves than i will lay both side by side on the ground in a 2.4x1m or 2x1.2m configuration than lay my NFT pipes over the top the whole length

Maybe i can link the tanks via a small 19mm hose and fittings so i am able to run two tanks possibly with different fish in either tank

So far the cheapest option is to use 90mm PVC pipes i could run 4 or 5 channels over the two FT

Or i could get all fancy and run two individual systems

I like the thought of running the two FT linked by the 19mm hose i could run Australian Bass in one FT and Australian Silver Perch in the other tank

You can do NFT or DWC (Deep Water Culture) For those systems, the bacteria grow on the surface of pipes, netpots and floating rafts. It's also recommended to have a filter to remove solids before they go into the NFT or DWC because solids get caught in roots and cause rot.

You will probably need more than just the pipes, pots etc for the bacteria, as there wont be enough surface area.
It would take a huge length of pipe with pots to be equivalent to a GB full of clay balls, and as Vida says above, you still need to remove solids before they get to the plant roots.

Thanks heap for the help from both of you i really appreciate it

What if i set up a bio filter as a sump? i could go either a 20 litre bunnings pale or even a 60 litre mini drum but im not sure how the waste from the fish will be moved around the tank to be sucked up by the sump pump?

If you are going to run F&D, your sump needs to be large enough to prevent overflows or running dry as the pump moves water in each cycle.
Actually, your system is a bit of a moving target ATM, so you really need to settle on a design

Are you planning on having a pump in the ST as well as the FT?

If you have a solids lift overflow from your FT into your ST, then you only need one pump in the ST. If you use one IBC as a FT, and cut the other to make a ST plus a gravel filled GB, you could safely put 20 fish in the IBC FT, and the half IBC with gravel, ~500l, would give you enough filtration. The SLO could go from FT to GB, then to ST, and pump clean water through NFT/DWC and return to FT.

Yeah i know I'm too excited about building something so i'm filled with idea's

I just picked up the IBC tank i purchased it from ebay for $25 but kind of heart broken when i arrived to pick it up and i looked inside, it was never washed out sitting outdoors under Gumtrees with the main lid off and all mud like crap inside of the tank on the bottom it smells like a creek, i was thinking of just paying the guy for it and leaving without it after seeing it

But i had to for fill my end of the ebay deal and take it home

I'm going to Bunnings shortly for grinder supplies while there i will get some timber to build a level space in the back yard

I plan on cutting the tank and frame than pressure washing out the entire container it is absolutely filthy and stinks

If I'm happy with it once it's cleaned i'm going to run just the FT for the next week with a basic aerator or a very cheap pond pump and5 bucks worth of gold fish to see if theygo belly up from the contaminants

The seller had so many of these containers he lost track of what was in it however he said it was good for fresh water and he said he is pretty sure it had olive oil in it previously

If this tank is usable I'm most definitely not eating the fish nor the plants haha this is just a hobby

You got a good deal at $25 if all it smells like is a swamp, its more likely that it had chemicals in it, check on that.

I just pressure washed most of it out and it indeed was olive oil there were some traces of green oil still in there, it doesnt stink like a motor oil and doesnt look like it just it stunk really bad like a creek haha it also had deteriorated gumtree leaves in the mix with sticks etc...

I just cut the tank as per the video on youtube but i really don't like how high the GB is

Do u think i can lower my FT to the next horizontal bar? that would work out to a 1 to 1 ratio there about

Didn't get a chance to wash out the GB as its getting late and the pressure washer was being temperamental

And the sneaky little B in my picture the Blue Staffy she is only 2-2.5 years old loves to get into everything and i suspect she may chew my wires if not carefully laid out haha i love my dogs so much i have 4 of them

I'd keep the FT deeper, the FT to GB ratio isn't really important- it's filtration volume to amount of feed that is important, and amount of feed is related to number and size of fish, not FT volume. Small fish eat a surprisingly large amount of feed for theit size. Of course you don't want to pack the fish in like sardines either!

Having taller sides means less liklihood of losing fish over the side too.

Thanks i have also decided to use clay balls and go with the F&D design for simplicity

Any idea on what safe product i can use to scrub and remove the oil with? i need a product that will break down the oil residue

Can you dig the bottom section of IBC into the ground? or build a small stool/walkway on each side of the system?

i wouldnt make the FT smaller either, 2/3 of an IBC is small enough already.

I'm trying to do this the easiest way my back yard is mostly on a slope but we do have flat sections just its on the other end of the yard, where i want to locate it is near my back door for convenience and it's much closer to the power outlet but its on a sloping ground roughly 100mm over 1.2m i can't dig because we are renting and our dogs have dug up plenty of the yard as it is

I may just have to leave it as is but when i grow peppers i may not be able to reach them haha

Do u think adding an additional 1x1 meter NFT system to my FT later on down the track will work or will i be over loaded?

adding the NFT will work fine, if there arent enough nutes later on then feed the fish a bit more or get a few more fish.