Backyard Aquaponics
A place to discuss aquaponics

Reviewed the system today - water is flowing from bed to bed. We need to do a bit of change - the incoming water needs to be above the grow beds, and the exit of course below. We had both coming into the same place but we decided we prefer above.

Even with below, the system was working. It seems to take about 10 minutes to fill all the beds and 2 minutes or so to empty. This is without gravel - so I am assuming those numbers will be cut in half.

All seems to be working well, small mods today and then tomorrow, fill with gravel!

Don't forget the pictures !!!

Pictures tomorrow when we finish the plumbing - I don't want to confuse people too much.

That doesn't take much

We don't really know what we are doing - just keep changing things until it works. I am sure someday it will all make sense.

Since we have large ponds, I think I am planning on using the tanks as "finishers" - grab some smaller fish (like perhaps 4 to 6 inches) and feed them up to edible size. This way they should be tasty and clean I am thinking - the ponds can be a bit muddy sometimes.

that is normal too

Okay - the big question of the morning - how many fish to use "load" the system. I know that we are talking 3 kilos per 100 liters (if I am not confused) but when you start, the ammonia conversion isn't working. So, how much fishies do I use?

I have 2 2,000 liter tanks for the fish and a sump of 1,000 liter. So far, my grow beds are 2,000 liters as well (will expand to 4,000 in the future)

2000L of GB suggests a FT support of 1000L, so 3kg/100 = 30kg of fish (when grown out) so I'd reckon 60 fish would be ok, as they're small now. Being that fish come to you so easily though. You may as well start with 20, then in a couple of eweeks if your system handles it add, more, and more and more until your 3kg/100L is reached, as you are likely to keep adding growbeds this may take some time to reach this limit.

Thank KudaPucat - but what does 20 translate to? Remember, I don't have to play with puny fish - I can start with 4 to 6 inchers if I wish. What percentage of carrying capacity is good to start?

hummmm dunno, never thought of it in those terms...

some members will dislike this sentiment, but if they're so common as to be expendable...

Just wing it if the losses wont upset you. Guess. I'd say 25% full load for cycling, but hey, i'm guessing. No use to yoou here I'm afraid.

Nope, losses will not upset me - since they are basically free - if any die they go to the chickens as collateral damage...

From an experience gaining point of view keeping as many alive as possible would be much better.
Imho, any fish suffering needlessly (even free ones) should be avoided at all costs

Cycling with 10-20kg of fish should be enough, around 10 percent of the normal max safe loading assuming ~150kg of harvestable fish in 5000L of water (3kg/100L).
Monitor the water quality and go from there, you can always add more fish later if needed

Hex, he's only got 2000L of growbed atm...
this will support long term 30-60kg.
Is your estimate perhaps too high?

KudaPucat - I do believe you are correct - he was assuming I had 5,000 liters of water, not 2,000 of fish tank. Besides, I currently only have enough grow beds to support 30 kilos of fish I believe. So, to start, I might go with 3 kilos I am hearing?

I am going to through in some pond water to get it going faster - and

I'd agree, whack in 3kg, then check your water quality, if after 2 weeks all is still stable, then double the load, keep doubling when quality stabilises until you reach your limit (keep adding GB so you never reach your limit - all hail the AP monster :-) )