Backyard Aquaponics
A place to discuss aquaponics

Hi, I have been interested in a marine aquaculture system but the waste caused can be very hard to get rid of, you can't throw it on a garden or else the salt will kill the plants.

There is a very sought after and extremely beneficial rock called live rock (due to bacteria and live organisms which inhabit it) which filters water in marine tanks due to its porous nature.

If you have one rectangle grow bed filled with water and live rock / limestone attached to a large circle tank (where the fish are kept) then is this in essence a marine aquaponics system?

Here is a sketch up picture of the system:



Live rock can be propagated by mixing it 1:1 ratio or even 1:2 with limestone. Then over time the Coraline algae and other beneficial bacteria will grow on the limestone making it live rock



As for the fish something like: Mulloway or something big

Open to all suggestions and information anyone my have, i also tried searching for marine aquaponics on google this could be a first

Nic

Nic

Don the FF was interested, using a novel way of dissolving salt out of concrete. Do a search on live rock.

Sounds good Nic, we would have to know weather the live rock would be able to remove the nitrates sufficiently compared to the nitrate absorption of plants. I would also take advantage the salt water and include a foam fractionator in the design to remove proteins. Your design lacks some sort of solids removal filter, this would be probably essential for your live rock to flurush as solid would soon accumulate in the bottom of you rectangle tank.

With a bit of tinkering I think your idea might be a winner. Keep up the good workmate.

Fil

The live rock does absorb and use the solid waste, have you heard of a berlin system? many people use them in their marine tanks it incorporates using a powerhead to push the water over the liverock which then filters the water.

If the waste built up on the bottom of the grow beds would inverts such as prawns or even crayfish eat it?

Also if the nitrates where still not at a sufficient level then i could plant xenia coral which has a very high absorption of nitrates and phosphates.

Nic

This is the basic design for the growbed, this way the water is forced over the live rock and then pumped back up to and into the tank.

If i have a few inverts like crabs or lobsters/crays just as my clean up crew they can help stir up the solids.

I will do this on a small scale when and if i get the $$$ to fund it, any suggestions as to what fish to grow? Has anyone been to golden ponds i hear they have salt water aquaculture fish?

Nic

Will be good to have some more discussion on this. its been brought up before, either by tim or don.

Last time i wasn't convinced that the liverock would be a net consumer of nitrate rather than a net producer.

not sure if its the berlin method that also has the anoxic sump at the bottom or another variation on it. What this does is create a zone where nitrate is reduced back to nitrogen gas, hence closing the loop.

will try and find a link to it, its very interesting, even uses the heat generated by the reduction to induce a very small water up draft from the sump to move the processed water out and the unprocessed water in.

But back to the live rock.

Live rock is at its peak price in W.A up to $30 per kg in some pet stores. I would say retail price (what we could sell at) around $10 a kilogram but still pretty good. I personally can get live rock VERY cheap (personally only) so i think i would buy around 20-40kgs and just mix it in with limestone.

The only problem i see is once the protein skimmers work what do i do with that gunk? i will be left with vast quantitys of muchy disgusting protein. For all the marine keepers out there cleaning out those proteins is the peak of our hobby

I personally use a berlin system in my marine tank but incorperate it with a small hang on filter just because i am very over protective ($600+ worth of coral in there). Even if you added a barrier after the live rock just a big piece of filter foam which cut down the end of the growbed just to block all remaining solids or even on the entry into the tank make a small pre filter out of wool.

My setup:





Nic

nice sized eleagance coral. they're fun to watch feeding. ours grew quite big in a short time.

i have heard it is hard to get good stock of them now.

U sure ur just 16 man? You explain ur reasoning/points in such a simple mature way u gotta be 50. C'mon man, fess up, I'm starting to feel like a 42 y/o dummy here!

Very interesting - how about kelp to be a consumer of the waste products of fish? Just a wild idea, but there has to be something in the ocean that uses the by products - just like we use the systems in fresh water.

Kelp could be harvested for various purposes as well

would need to be a cooler water system, i think kelp prefers the cooler waters. good idea.

Shows you how much I know about kelp... But surely there is something that would be a consumer. I would say sea cucumbers... but they aren't plants!

Kelp is great, but temperate waters are REALLY cold compared to backyard systems. The max temp is about 15C. or 59F It's very hard to do this without chillers as Steve noted, and Nic wouldn't be able to keep all that beautiful coral at those temps.

He could keep nice sponges, and cool fish I can catch from the local pier... A shark tank'd be cool. We have some nice fish in temperate waters, not that a marine aquarist would belive me. They seem to think our bays are full of colourless boring fish!.

Aside: Steve, when are you getting your diving licence? I've not seen muc on the SCUBA steve thread :-)

brothers doing relif shifts for all the managers that have gone one leave no point doing it with out him really.

so??? shift = 8-10 hours a day, that leaves 14-16 free to dive :-) Not to mention all the extra cash he'll have to spend up big on gear... but this aside is rapidly becoming a hijack :-)