Backyard Aquaponics
A place to discuss aquaponics

hi guys, I am new at this. first post, read heaps but can never stop learning, but does it matter if my biofilter is before the plants. floating system or should it be after it,.
the way I see it is the plants want nitrates so I have it before it goes to the plants.

the plants are doing ok but not fast enough as putting them in the garden, planted at the same time is.. this normal.

I can move the biofilter after the plants so the plants get all the waste and put it after the plants eat..

there are only 50 guppies in 1 IBC and 20 prawns in another IBC and the biofilter is in the other made up off plastic media and a few crayfish ..

water is clear

TIA for your advise

Do you have a DWC (deep water culture) type system, or a media bed (gravel, expanded clay)?

How old is the system?

A single passing of water through a bio filter does not completely convert ammonia through the processes into nitrates for plants to uptake, it does not happen instantaneously, so it won't matter where the bio filter is located within the system (with respect to nitrates)

you need to add some fish, too much water too little fish stock, can't provide enough nitrates for such a large system

Colum Black-Byron Im trying a deep water culture/ floating

thanks bunson sounds good

oswinmark, I thought the same I need a lot more fish to help the plants...

getting more fish soon, and might put some stormwater pipe around the fence and back and put some 50 mm pots in with more plants.

is it advisable to have heaps of air bubbles in the biofilter, will it make more bacteria????

made a worm farm today hope I can feed the fish some soon

thanks for your reply's only new at this and its doing my head in , in all the theories

It has proven time and time again that systems can very well on just a few fish, and it has been proven time and time again that too many fish leads to deaths system failure.

Exactly how much filtration do you have; this will tell you how many fish you can keep.

How old is the system?


If you're attempting "moving bed bio filter" technique, you just want the media sedately moving in the water (or water moving through the media) and that water to be well oxygenated. Pumping too much water or air through the media is detrimental. You cannot "create" more bacteria than the media will hold -- it's all based on surface area. If you want more bacteria, add more objects with higher surface areas, within limits.

bunson, thanks for your reply, I have a IBC full of gutter guard plastic as my media (cheaper than real media) and have a small air stone in it . it flows from the other 2 IBC slowly through each other and through my deep cycle grow bed and pumped back in again.

as I don't have many fish in the system yet , will some chicken poo help with the cycle???

what does oyster shells do? does it raise or lower PH, steady at 7.4 at the moment

TIA

Cheaper, yes. But, significantly smaller surface area per volume. Sand has a remarkably high SSA (specific surface area) of about 4000m2/m3 (but this causes other problems), Kaldnes mini is about 900m2/m3, Kaldnes K1 is about 500m2/m3, hydroton is about 300m2/m3, 20mm gravel is about 100m2/m3 (all from memory) and I think you'll find gutter guard has even less SSA?


So long as there is water moving sedately throughout the entire filter, you shouldn't have any troubles. If you develop "still water" in the regions in the filter, this is bad as those regions can become anoxic/toxic as wastes will start to breakdown anaerobically.


NO! Do not use waste from warm blooded animals in a system which is going to provide food for human consumption.

It can take up to six weeks for a system to fully cycle... patience is all that is required.


Oyster shells, shell grits, limestone etc act as buffers in the event of falling pH (acidification). Buffer materials generally wont dissolve in "higher" pH so will remain dormant until the pH starts to fall; hence their use a buffer agents. If your system is not even cycled, do not play the pH, let nature take it's course (but as you've already got fish in your system, you are going to have to be mindful of their welfare) You don't need any buffering atm.

ok put 50 jade perch in there about 4cm, see how we go

does it matter if I don't have a solids filter set up and just siphone out the bottom once a week which will do a water change as well. the solid can not get to the grow bed
my water is clear its just the bottom

ph is 7.8 - 8.0
amm is .25
nitrite is 0
nitrate is 0

is that OK

my plants, like corn and tomatoes don't seem to be growing any like they have stop growing they are still green, but I started some lettuce and spinach on a floating piece of foam and they are growing great, I don't know why they have stopped growing it even has tommys on it

That's a lot of silver perch for 1 IBC. You're going to run into problems if you don't have the right filtration, along with the surface area needed for converting the bacteria doing all the business.

Can you post some pictures of what you've got currently? I don't want to see you loosing your fishies.

I wouldn't try corn in DWC, it'll get tall and fall over too easily, anything top heavy needs to be strung up, and I don't think corn is easy to string up.

I have 3 IBC, 1 is filter, and 2 for fish 25 in each

I have wire around it to string it all up, but it has stopped growing for some reason

TIA

Nice, where'd you get that surface area info Bunson?... I didn't realise there was such a big difference between expanded and 3/4" blue metal.

Bluestar, I have never grown Jades, but I have it on good authority they are slower growing than Barra, but faster growing than Silvers. Barra require 25L+ of WET expanded clay gravel each for sufficient bio-filtration to safely get them through to plate size, Silvers being slower growing only require 20L+ of WET expanded clay gravel. So your Jades will be somewhere in the middle, but I would go the 25L+ ratio just to be on the safe side... that was the easy bit, now the hard bit... You need to figure how to relate your bio-filtration media (gutter guard) to expanded in regards to surface area.

I'll throw some of my own opinions in at this point for your consideration:

a). In an aquaponic system, gravel filled GB's are the cheapest, easiest, and most practical method of creating bio-filtration... plus they fulfil two roles, as opposed to just one in the case of your bio-filter.

b). In your location I'm assuming the summers get rather hot, if so, I wouldn't be running the pipework with pots in it around you fence line as you've suggested you may do... you will be creating a brilliant heat exchanger... with the heat going the wrong way... and you will also be de-oxygenating the water.

How do the plants look? Yellowing leaves?

If you didn't have the filtration up and running, the solids can cling to the plant roots, and block nutrients being taken up, it'll cause stunting.

Another thing I had was the plants falling over and damaging the roots, or swaying and rubbing and damaging the roots.

I don't know how much 50 guppies would put out ammonia wise, so there might have need a nitrogen deficiency (might). And what's your PH sitting at? It could have lock out issues.

firstly thanks for the advise, I don't think I will be able to put it in buckets on the fence as it will be way to hot.

filtration has been up and running, recently when I put the fish in I put the swirl filter in and works great.

my tomatoes are yellowing and stunted but my lettuce is going ok, my duck weed is going nuts in the containers

ph is 7.6-7.8
amm is .25
nitrite is 0
nitrate is 0

all are still alive, water is clear

Byron, if I have lock out from the roots, can I cut the roots shorter so it will let the plants get what they need