Backyard Aquaponics
A place to discuss aquaponics

What would happen if you had fish in a tank and had a grow bed connected as a filter but had no plants in it?
The reason I ask is I wonder if it is feasable to grow fish inside some stables with no natural light just using a biological filter.

im in experienced but I would say that the nitrate levels would keep increasing and noting to reduce them as thats what the plants do, a question for the more experienced however, in the darkk or with minimal light would that nitrite to nitrate conversion take place, ie would it or wouldnt it cycle with the correct bacteria growth?

Bree

You will have to treat it is a normal fish tank and do regular water changes, the amount will depend on the stocking density. A highly stocked tank will probably need a 10% water change every second day.

the ammonia will still brake down into rites & rates which is much better for the fish to deal with!
this is called biofiltration and would be a good thing, however there are lots of shade loving "house plants" that will thrive in low light, AP dont have to be vedgies you could have ferns or lots of other nice plants.,

Oldute,

I have three tanks in my Garage with bio filtration only. Fifty trout in a 1000 litre BYAP tank and 15 in a 800 litre IBC tank. Another 1000 litre BYAP tank has 20 bream. All these tanks have a bio filters (100 litre water tanks from Bunnings) containing hydroton, marine shells and foam. On the top of the filter I have dacron matting used as a fines medium which I clean at least once a week. As mentioned above, nitrates in the system will build up, so water changes are needed. The most frequent change I do is on the 50 trout tank, every three days....approx 15 to 20 %. This is probably overkill though as nitrates have never reached 100ppm.

my garage fish pond with DIY bio filter

Bentaz, how does that filter work?

it is made of 250mm pvc pipe filled with a mix of bio balls( to bloody expensive) volcanic rock and a sh*t load of 1-2 inch bits of old hose / pipe!
works a treat, the original plan was for it to be 7 ft tall but it was unstable and wanted to fall over in the presence of children, hence it is in the pond where they cant get to it and was cut down to about 5 ft high, if building it again I would put the drain tap into the bottom as it was a real prick to seal it into the side, I would then stand it on some bricks or the like!!
Hope that helps!

Maybe a better discription when im sober lol!

It is a scale model of a water recycling plant from tialand only theres was 50 ft tall and turned sewerage into drinking water.

Yup, you have to treat it as an ordinary fish tank. The gravel bed will still host the bacteria that you need to convert ammonia>nitrites>nitrates but you will miss the additional bio-filtration of the plants. Of course, you can reduce the fish bio-mass and make regular partial water changes. Good luck.

sorry double posted the same pic ment this one to be in there.
Just put some ferns, or any shade loving houes plants in there,

My indoor fish system is 800 gallons. It has no plants and I purge up to about 50 gallons a week from it (6.25%) and often less. I have never had nitrates above 5. It does have an anaerobic part, but im not sure how much that removed nitrates. I am confident that you can rise fish without plants, but then that is what recirculating aquaculture is all about..

This system has been running for well over a year. Currently it has about 300 fish in it.

Why not run the water from the biofilter through some NFT channel or similar along the outside of the stables to grow some fast easy to grow plants such as lettuce, english spinach and basil to remove some nitrates. It will reduce the amount of water changes needed and give you another produce. I have some NFT channel being fed from a feed off my biofilter and it works a treat. I would love another 50 meters of it to set it up properly. Thread is here viewtopic.php?f=18&t=5478

Thanks for the info everyone.
I think I'll use a bio-filter and run some water off it for some plants as Burnsy has said.
Biofilter should be a good way to keep ammonia under control without the need for lots of grow beds.

I would guess that those plants would take up more than 50 gallons a week.