Backyard Aquaponics
A place to discuss aquaponics

I probably feed a tablespoon of pellets and a few pinches of flakes -- three times a day. Plus a few radish leaves or a small scoop of duckweed. If you look at the charts, they recommend feeding 10% of their weight in food a day at their size. Guessing that they are about 4-5 grams each now, that would mean giving your fish about 28 grams (an ounce) of food each day.

Base the amount you feed on the water quality, not on how much they want. (They want the whole bag, actually. Now.) Even though I had been cycled up with 6 goldfish for at least 6 weeks when I got the tilapia, it was still a strain on the bacteria to keep up with them initially.

Hi bhsx,
The wasabi appears strong and healthy, but leaf growth is slow right now. My basil is growing pretty slowly, too. I suspect the problem is the short days. I've been having a little problem with aphids on the wasabi too, but nothing that can't be handled with a little squishing and a small shot of insecticidal soap in the crown. (I've done that several times with no adverse affect on the fish, btw.) It had appeared that the wasabi wanted to bloom shortly after I got it, but I think they decided against it. Maybe transplant shock talked them out of it. They were a bit rough to transplant; I initially lost about half the leaves on the plants. In truth, I should have anticipated that and trimmed them back to start with. So the jury is still out, but I still consider it to be promising.

The folks at our favorite Japanese restaurant are very interested in the wasabi progress, too. Wouldn't that be a cool market.....hmmm.

Janet makes a good point...

To lessen transplant shock... cut the leaves in half... reduces amount of transpiration (by 50% I guess) while the root system has a chance to re-establish and commence water/nutrient uptake....

Takes a day or two for the roots to start transporting water... so any transpiration is no longer balanced by water uptake until then...

hence reducing the surface area of the leaves reduces the potential transpiration loss

Do you plant that from seed or cuttings? Sounds like a good niche crop. What part is consumed? Do you eat the leaves or the seeds or what?

I am glad your fish are doing well.

Hi DT,
I purchased 3 wasabi plants. It makes side shoots that can be divided to make new plants, and that is the common way to propagate it. It also makes seeds, but I guess that is harder. Mine has been making plenty of side shoots, btw. After the plant grows for a year or two, the root is harvested and can be grated to make a condiment used with sushi. The leaves are apparently also edible and rather attractive. It is native to cool shady mountain streams in Japan, but is also grown in the mountains of Washington state and North Carolina now, too. Here's a link to the place in North Carolina... http://www.realwasabi.com/

I've been struggling to feed the poor hungry tilapia as much as they want. But if I give them as much as they want, the nitrites start to spike. Doing some math, I figured out that:

a) I was turning over the tank volume about every 1.5 hours. (That's a bit lower than I originally envisioned.)
b) The grow beds don't take nearly as much water to fill as I thought they would. I originally calculated that a 50 gallon grow bed would need 25 gallons to flood. In reality, it takes only a bit over half that.

I re-worked the auto-siphons so that they dump the growbeds a lot faster. I went from half-inch (12mm) to 5/8 inch (16mm) tubing. Although it doesn't sound like much of a change, the cross-section is 50% larger in area. Then, since the water was dumping faster, I could turn up the pumps. I now have the beds on continuous flow, with a fill cycle of about 8.5 minutes, and a drain cycle of 3.5 minutes. The filling drifts in and out of synchonization, but it's OK. The tank volume turns over about twice per hour now, and voila, the nitrate spikes have resolved. I had originally been worried about too much fluctuation in the water level of the fish tank, but since the grow beds take less to fill than I thought, it's not really a terrible issue. I've ordered a larger pump with a gift certificate I recently received, and will be re-plumbing the inflow to the beds to try for a turnover of 3x per hour or a little better. It doesn't matter how big the growbeds are if you don't get the water moving through them! That should give me the capacity to let these tilapia grow a bit.

I've also started up two 50gallon aquariums for the "Love Shack" and fry grow-out. Each has a goldfish in it right now, but the goal is to have them both seasoned by the time I have to sort females from males around the end of March. There's more and more posturing going on, and the tilapia certainly can tell the boys from the girls (and the boys from the men!), even if I can't yet. "King Speckles" is looking like a good candidate for my male. (He's the only one that I'm sure of the gender, and also the largest fish in the tank.) I originally thought he was too aggressive, but he seems calmer now. There are a number of medium-size fish that are nice and white and plump that might be my females. We shall see.

Janet, its amazing what a few minor tweaks can achieve, the difficult part is to not make major disruptions that upset the balance (keep repeating the "P" word )

Hi Janet:
My system is something like 6 minutes peak-to-peak for each bed, about 12 gallons to fill (when the ratio was measured I got close to 50/50, but this is 1/4" gravel so maybe that is the difference) so say 40 gallons every 6 minutes is like 400 GPH, or about 3x turnover per hour.

Have a definite leader of the pack now, looks like a large mouth bass compared to the other ones.

I am feeding them about twice as much as before, or about two tablespoons of the crushed bronze per feeding which is two or three times per day depending on if I am home. How much are you feeding yours ATM? Mine still act hungry all the time... Maybe we should calculate how much food they will use to reach eating size when they should?

I'm feeding about the same amount as you, Dave. They act like they are starving pretty regularly. They are worse beggars than the kids!

Fish have a feed conversion of about 1.5:1. So 1.5 pounds of food will produce 1 pound of fish. If you raise 30 male tilapia up to 1 pound, there goes one of those bags of bronze food you brought me! And that's not counting the food the females (or my goldfish) eat, too. I was working through this math when I was deciding how many bags of food to have you bring me. I was kind of balancing between taking advantage of such a good price, and not keeping it on hand so long that it lost vitamins.

Wow,

I am impressed! The fishies look happy. Has the lid taken care of your temp problems? That is going to look simply gorgeous when it is booming with plants!

Anna

Hi Anna,
The lid helps retain the temperature quite well. The air temperature underneath the hood gets quite warm and moist, so I can tell it's helping with both temperature and evaporation loss. I have added an extra support to the front half--it was starting to sag. I also learned that aquarium sealant is not the best for adhering bubble wrap to a surface that flexes frequently. So the rear half of the lid still has bubble wrap on it, but the front half does not.

Regrettably, my large heater failed the other day. I called the manufacturer, and sent it in for repair/replacement. So I'm running on back-up heaters which are barely sufficient. The lid is really saving the day. When I re-work my plumbing, I think I'll add more insulation.

Does it ever stop?!?!

Not if your a true AP'ier. LOL

The evaporation would be huge without closing it up somehow, for sure!

Show them Fat Fishes again.

A piece of blue board cut to size would work nicely. No sagging and no water loss.