Backyard Aquaponics
A place to discuss aquaponics

I've never taken the trouble to weigh fish to figure out feeding.
I usually just feed an amount that they will finish off in about 15 minutes. In the beginning I would measure out an amount of food and give it, wait and see how fast they eat it, if it's all gone really quick I would give more (keeeping track of how much) and keep this up until they slow down or stop eating. Then figure out how much food I gave and then give them the same amount all at once on the next feeding and make sure they finish it all off in about 15 minutes.

Then every few days I would increase the amount of food given by just a little bit but still keep an eye on things to make sure the finish it all and also keep an eye on the ammonia/nitrite levels to make sure spikes don't get out of hand.

Weighing the fish to figure out feed is an activity for a commercial operation where wasting feed is wasting profits.

Thanks Tcl. The trout are still ravenous. Do you do the "as much as they can eat in 15 min" once a day or more often. I finally got another load of stone in and spent yesterday washing stone with two friends so now all four growbeds are full of medium and plants. The water is murky again as a result but I am sure it will clear. The trout are lightning quick and impossible to net in the small net. I am busy making up a net from a piece of 15% shade cloth and some weights and floats to do the catching job. I am dead keen to try out one of these trout soon. The greens are really growing very well and we are having delicious salads with lettuce, rocket, swiss chard and pac choi daily now. The lettuce are twice the size of the ones in the dirt garden. very cool I am also working on a new shade roof for the fish tank as the previous one was a pain from a viewing feeding and netting point of view. I now have a plastic fence leap of faith preventer and a more lofty shade roof in the pipeline. I have also been working on the small system growbeds, getting them mounted on their stands, and clearing up the general area for the installation.

Sounds good. I usually set the feeder to do 2 or 3 feedings a day. Now that I have only catfish it is just feeding at dawn and dusk but when I had tilapia I also fed in the afternoon.

I set the feeder so that if I come by 15-30 minutes after the feed, there shouldn't be any left floating. I will increase the feed time by a few seconds regularly as long as none is left over, I figure I can keep upping the feed a little. If there is some left over for more than two feedings, then I know I need to figure out what is wrong and test levels as well as reduce feed. Of course as water cools with catfish, the feed needs to be reduced. With trout you have to watch both ends on feeding if it gets too hot you need to reduce feed and I'm not sure but when it's really cold I don't know how much they feed.

Anyway, Some people feed three times a day, other only twice and if you can only be consistent on time once a day, the feed once. It is kinda important to be consistent on feeding times because they will get used to a schedule. Sometimes it's hard to get their attention for feeding if it isn't the normal time.

Ok Tcl. So far I have just been chucking in a handful when I go to the system but I am going to move over to a more regular time and amount. I managed to make a working net and netted myself a trout for dinner. Fried it up in some butter, olive oil, salt and pepper and had a side salad. It was truly awesome! .

home grown meal nothing much better than that
Congrats

some pics of the new roof structure. This roof is cool cause it allows access to flies and insects and I can hang the maggot machine up there.

That yellow plastic container has roadkill in it. I am hoping that the fly maggots land in the water.

parts for the new system.

System is looking pretty good Brian - and congrats on the first trout eaten

Thanks Chilli. The salads and spinach are awesome. I am concerned about the pH. It has gone up to a scary 9.5 now. Should be worried about this? The fish seem to be fine with it.
At least they are not showing any signs of stressing out. Hmm, what to do....

I have maggots in the road kill. I am just wondering now... will the maggots try to go up or down once they are done. There are a few small holes in the bottom of the container for them to drop through. Is there a theory to this?

My Ph went up to 9.5 or higher fairly fast after I filled my tank. After a couple acid treatments i realized something was buffering it there but the concrete was sealed.
Eventually I found out I had some concrete slag in the bottom drain from the water escaping as the concrete dried. Since I got that out I have drifted down to 8.2 which is my normal water Ph.

From my experience maggots generally head to the light, so perhaps cover the top and have a couple holes in the bottom.

Well the pH is now back down at around 8 but . I am getting plenty of solids building up in the beds where the water floods in. Mostly uneaten food. It is pretty gross and I am wondering what to do about this. Get worms for a start I suppose. I find that the water really flows into the beds quite fast and wets a large surface of the growbed and the solids get distributed over a large area. is there not some way of limiting the spread and having some kind of removable filter to catch the solids, something with a removable medium in it like a pvc pipe with shade cloth in it. like an rsg filter but for solids.

I am getting some aphids starting to colonize a few of the weaker cabbages. My current strategy is to sacrifice the plants as they are the weak ones anyway, but aphids are going to be a major pest for me. What is a good fish safe treatment for aphids. Soapy water is probably a bad idea....

i used the chilli powder/garlic/pepper home made spray, it helped with regular application (like 1xwk, or after rain), i found it on the forum..

Thanks Keith, I will give it a go. I am thinking of using some womens stockings fixed over the ends of the growbed fill pipes to strain out the solids. It is pretty gross as it lies on top of the stones and kind of grow into this weird white fungus moldy stuff.... yuk. I am really amazed at the speed at which the trout are growing. There are some monsters in there. I must start to organize a smoker. when temps go up I am going to need a way of preserving the fish when I take them out, and I recon smoking will be a good option. I finally got a fence around the whole system, and in the nick of time as the buck had discovered it and had munched a lettuce and pulled up some of the beetroot the night before. Not as much damage as could have been inflicted but now it is safe. The maggots are really pumping in the road kill box. The last couple of fish I have had where getting plenty of maggot. I could see from the contents of the stomachs.

Have started working on the growbeds for the greenhouse system and have been playing around with autosyphons. I am finding that the level of the autosyphon standpipe needs to be considerably lower than the desired water level. Is this normal? I am using 32mm standpipes with 50mm outer sleeves and 110mm pipe to keep the gravel out. Is this ok?

Right, worms are sorted out and the solids are no longer a problem. Very efficient are the worms. I also now finally have a good fence right around the system and have installed a pipe for drippers and I am going to plant this reedy stuff along the fence as a windbreak. The wind can get hectic here. I have also got the smaller sump tank installed in the ground and the autosyphons done on the small growbeds. Some pics