Getting Started

[Felipe Cohen]

Hey everybody,

 

I would like to have some feedback about my first aquaponic project. Unfortunatelly I could not put some pictures. However I can give some description of my project. One fish tank (500 litters) and four veggie tanks (for about 70 litters each). I want to grow Tilapia, so if there is any suggestion about the number of fish (is 25 a good number for 500 liters tank?), pump power (is 3000l/h enough?) would be of great help.

Best wishes,

Felipe

 

[TCLynx]

Base the number of fish you start with on the amount of filtration you will have set up when you start.

So 4 x 70=280 liters of filtration.  (if 500 liters of media filled grow bed is good for starting out with 20-25 fish) then I would say start with half that number of fish.  So 10-12 fish for 280 liters of media filled grow bed.

 

If you are doing raft beds, well then you will need to base the amount of fish on the amount of filtration you will be adding, 4, 70 liter tubs of rafts will not support many fish without extra filtration, probably more like 2-4 fish.

 

 

 

Pump size will depend on how you run the system.  If you are running with a timer where the pump is only on for like 15 minutes each hour, then a 3000 l/h pump might be enough provided the pump will still move at least 2000 liters per hour at whatever height it has to pump above the surface of the water it's pumping from.  If you will be pumping constantly and using siphons or constant flood, then 3000 l/h should be plenty as long as you are not pumping very high.

 

Upsize your plumbing for better pump efficiency and definitely go larger than the pump line for all your drain lines.

[Felipe Cohen]

Hi TCLynx, Thanks for helping me. I was also thinking of putting les fish (10-12) but will this produce enough nutrient for growing plants spread in 4 half-gallons (70 l each)? Also depends on fish size doesn't it? if I start with 12 small fish I migh have to over feed them to produce enough nutrient, don´t I? i believe that is dificult to answer, but how many plants can I grow in this system (includding only letucce ans small veggies)?.

It is almost 2m high from the bottom of my fish tank to the plant tank. I intend to leave it in constant flood. Do you still think that 3000 l/h will be enough or do you recommend something else?

 

[Felipe Cohen]

Correction: 2m is too high..I think it will have 1,5m at most.

[TCLynx]

Head height is measured from the water level in the fish tank not the bottom of it.

If the pump runs constantly then I expect that pump will probably do for you just make sure to check it regularly to make sure it isn't clogging up.

 

New systems cycling up with small fish often take quite a while to cycle and produce nutrients but if you were to look up fishless cycling you can have nutrients before you even get the fish.

 

Small fish are usually fed higher protein feed at a higher % of their body weight and so to an extent they make up for being small so this issue is usually not as big a problem unless you are expecting full heads of lettuce 4 days after you sprinkle the seeds (and that is more a patience issues than an amount of fish issue.)

 

during a first season it is sometimes recommended to stick more with the leafy green plants since it takes some time for the more complex bacteria to really get going in an ap system and break down the solids to give you better nutrients for fruiting plants.

 

I say go for it and start working on your plans for adding more grow beds because I don't think you have enough.

[Felipe Cohen]

Thank you TCLynx I'll set this up with few fish (10) and I'll keep monitoring ammonia and nitrates level. Any other question I'll came back for help

[TCLynx]

There is also always the option of Fishless cycling (less stressful to you and the fish)

[Felipe Cohen]

I'll definitely do fishless cycling, the same we do for aquariums. 10 is the number of fish I intend to put after cycling. Do you think it is a good number? I'm thinking of putting some plants after nitrites get close to zero, is it correct?

[TCLynx]

You should be able to start plants pretty much right away, you don't have to wait for those.

 

If the tubs are going to be media beds, then yea you can probably handle 10 fish.

[Felipe Cohen]

Very interesting...I haven't start yet. I'll put the plants right away then!! Thank you again..

[TCLynx]

if starting seeds they don't really need much nutrients for a while and when doing transplants they will probably need some time to recover from transplant shock before they are in need of much either.  A bit of seaweed extract to help give em a boost and provide trace elements for when the nitrogen cycle comes online and you should be pretty good to go.