Backyard Aquaponics http://backyardaquaponics.com/forum/ 

Calculations? http://backyardaquaponics.com/forum/viewtopic.php?f=11&t=27957 
Page 1 of 1 
Author:  Valodja [ Nov 18th, '16, 05:13 ] 
Post subject:  Calculations? 
Ok people. Correct me if i am wrong. I have researched and this is what i have came up with. To calculate how much fish in tanks is need for how much plants per sqm. 1kg = 42/45L In tank of 950gallons or 3590l that equals aprox. 85kg fish (common carp). Adult fish eat 13% of their bodyw.per day. If i use UVI g/m2/per day and take that fish will eay (1014months old fish) 2% of her bw...i get this. 85kg/tank=1700g fish feed. 1700g/1700m2/per day. So i can plant on 1700sqm... One 1sqm can be grown from 2030 lettuce..lets say 20....that would be 34000 lettuce...is that posible or am i complitly wrong? 
Author:  dlf_perth [ Nov 18th, '16, 08:35 ] 
Post subject:  Re: Calculations? 
OK  quite a few variables... fish species along make quite a bit of difference in addition to what you actually feed them and how active they are. Active = respiration / energy burn = ammonia. The stocking density is 85kg for 3600Litres  so you are talking 85 fish = 1 fish per 42 Litres ? to be honest in a fully commercialised setting you probably be working to 500g base stocking with a grow out, so more like 160 fish in 3600 litres to the 500g point and then constantly destocking at that point (fish growth varies anyway so you will be grading by size for market grow out). that achieves around 1 fish per 2025Litres which is manageable with appropriate filtering etc. lettuce etc is always grown on a cyclic basis  so you always have a mix of new, various stages and ready to harvest. 20 to 30 lettuce per sq metre is pretty reasonable to expect. In a square sqMetre you could have a 6x6 array of cells. (1 lettuce has around 150mm to grow). There are photos of commercial level lettuce rafts around the forum and these will give you an idea  eg pic here viewtopic.php?f=1&t=17591 plus dasboot thread will have some pictures. 500g1kg of fish would support 20 lettuce of various stages. as a BYAP guide a IBC fish tank (900L or so) with 2030 200400g fish (ie. SP or Tilapia for example) will support 3 grow beds/DWC combinations full of mixed veg. So basically 9kg fish to 3m2 or 750Litres of media. so that is saying 23kg fish is easily sustaining 1m2 of full veg. Lettuces are much less demand so 1kg for 20 lettuce of various stages = no problem. A well balanced commercial setup should be much more efficient. 
Author:  Valodja [ Nov 18th, '16, 22:41 ] 
Post subject:  Re: Calculations? 
Ok. i get the pic. Just the thing is. I don't get this calculations. One question, different story.... It just seems to me that 85kg of fish (grown 12kg) is normal for 950gallon round tank with cone bottom. Its a tank dim..96"*36". I think that much more can be placed in such tank. 
Author:  Know expert [ Aug 18th, '17, 00:40 ] 
Post subject:  Re: Calculations? 
Vallejo..... Hello, I know I'm late on this one but I'm replying so others can see what you've done. You follow the UVI ang get it right up to the 2% body weight being 1700g of feed but then you make a slight error and say that's enough for 1700sq m of grow beds when it's actually just 17 sq m at 100g Per sq m or 28 sq m at 60g per sq m. 17 grow beds at 20 lettuce per bed is 340 and somewhat less than the 34000. I'm sure you figured that out though....... KE 
Author:  Nadine Drechsler [ Apr 14th, '19, 00:11 ] 
Post subject:  Re: Calculations? 
Valodja wrote: Ok people. Correct me if i am wrong. I have researched and this is what i have came up with source. To calculate how much fish in tanks is need for how much plants per sqm. 1kg = 42/45L In tank of 950gallons or 3590l that equals aprox. 85kg fish (common carp). Adult fish eat 13% of their bodyw.per day. If i use UVI g/m2/per day and take that fish will eay (1014months old fish) 2% of her bw...i get this. 85kg/tank=1700g fish feed. 1700g/1700m2/per day. So i can plant on 1700sqm... One 1sqm can be grown from 2030 lettuce..lets say 20....that would be 34000 lettuce...is that posible or am i complitly wrong? I started cycling without fish 7 days ago. I managed to obtain a bottle of ammonia, 12%, but it has traces of chlorine(ppm). When I saw the chlorine part, I decided to use fermented urine. as the ammonia source. 
Page 1 of 1  All times are UTC + 8 hours 
Powered by phpBB® Forum Software © phpBB Group https://www.phpbb.com/ 