1.2 Angel tank.

I currently have something that can deprive a person of sleep like few other things can, an empty fish tank.



At least I know that it is going to hold angels. I've always liked angels, but never kept them before because I didn't have the proper sized tanks.

One thing I intend to do a bit differently from the normal aproach is to grow plants externally from the tank in a different container aka aquaponics. The idea is that the terrestrial plants will extract nitrogen waste from the water as long as the other nutrients are kept at sufficient levels. The plan is to keep only relatively "easy" plants in the tank. The aquascape will rely mainly on wood and rock, with green provided by plants like vallis, anubias and java fern. Maybe some floating plants.

Tank size:
120 x 50 x 50 cm.

Substrate:

Smooth silica sand with pieces of slate mixed in to darken the overall color of the bottom.
I would actually prefer a dark substrate but I am yet to find an inert, smooth, dark substrate.
I saw them selling filtersand at the petshop, can I just pick that up at the hardware store?

Plants:

Vallis, anubias, java fern ... open to suggestions. ( light will be moderate but I'm flexible on that, might vary it across the tank )

Lighting:

To be decided - Either tubes, CFL or DIY LED. I am leaning toward CFLs because they have served me well in the past, cheap and easy.

Filtration:

Minimal mechanical filtration using filter wool, biological filtration via hydroponic plant culture combined with normal bacterial biofiltration before water re-enters tank.

Heating:

Normal thermostat-heater units plus additional one in external containers to heat water before re-entry into tank.

Fish:

5 or 6 angels? I am hoping that they will start breeding so at that stage I am not sure if the best aproach is to remove the breeding pair from the main tank and then put them back later or to try and remove the other fish from the tank. Can I just leave them all together while breeding? I guess it depends on the personality of the fish?

Corydoras - 8 Exact species to be determined based on advice and availability.

Tetras - I'm thinking a school of Rummy nose tetras but would like some advice as to which tetras are best suited for co-habitation with the angels. I've read that hatchet-fish are a good idea as they make the angels feel more secure.

Plec/ancistrus - Some advice pls!

I want to keep the stocking levels quite low. If the plants need more nutrients I will beef up the fish stock with more catfish.

External plants:

Strawberries, tomatoes, peppers, cucumbers, ??


I think that I will probably need to dose the water with micro-nutrients when the external plants use them up. Phosphates, nitogen and CO2 should not be a problem. I actually want nitrogen to be the limiting nutrient.

Has anyone else done an aquaponic setup before? Any other advice? Is the aquaponics a very bad idea?
Comments appreciated!

 

Hi Pulsar,

We have obviously been in touch by pm and I glad that there is another scientist on the forum.

May I say with regard to your plans, what you propose sounds very attractive on paper, but that there are fairly huge conflicts which I want to make you aware of. You may not be aware of this, but I developed fertilizers for aquatic plant growth and supply these to aqaurists. In developing these I had to work my way into hydroponics as well, because a lot of aquatic plant nutrition is just simply based on that. The conflicts that you sit with are that plants such as vegetables in hydroponics require a quite high concentration of inorganic ions such as Calcium and Magnesium. This leads you into conflict with your fishes because the fishes you propose to keep are all South American which come from extremely poor Calcium and Magnesium containing water. We of course call Calcium and Magnesium content general hardness in fishkeeping terms, but this has to be very low of these fishes. These fishes do well here in the Western Cape because our tap water contains just about no Calcium and Magnesium, but these levels are far too low for growing vegetables I fear. Tomatoes are guzzlers of Potassium additionally, and so the conflicts continue. I am asked ever so often by the Agronomists at Stellenbosch University to give them advice for their hydroponics, and from them I also hear that hydroponic mixes are quite different from one crop to the next.

So, my advice would be to keep these two ideas separate, as on the one side the fishes are not going to be happy and on the other, the vegetables are not going to be happy, so both things are actually not going to work.

Just my opinion on the matter.

Kind regards,

dirk

 

Thanks for replies. Guess I'll have to do another tank, with Tilapia or similar, for the hydroponics - and fertilize it properly. That has been documented to work elsewhere. I was wondering if there would be conflicts... now I know. Theoretically, I should be able to grow amazonian plants in this way with the soft water? You guys know of any edible amazon plants?

So, I can't do the aquaponics, then normal biological filtration will be used to remove ammonia and nitrites with a weekly 20% water change for the nitrates. I've used reverse undergravel filters succesfully in the past but I think in this case a sump would be more appropriatte. Comments?

Since there will be some plants, and as vallis is a rapid grower, will I need to add fertilizers? Plants are not really my priority here but I dont want a bunch of yellow and dying plants.

What is a good number of angels for this tank size? I've read that if you keep 2 or 3 there is likely/possible going to be some fighting, and people usually recommend 4 or more... What do you think? I thought for a tank this size 5 or 6 is fine. I would actually be satisfied with just 4, is that better?

For breeding purposes:
As I see it, the recommended plan of action is to remove the breeding pair from the main tank and put them in their own private tank. For angels I've read of people using 2ft up to 4ft tanks, what is the best? I'd like to raise the fry to a size where I can sell them or give them away.

@Reedfish The idea with aquaponics is that you siphon or pump the water out of the tank and use it to whet plants that grow externally in inert substrates. Then you pump the water back. So it would not take up space in the tank.