Backyard Aquaponics
A place to discuss aquaponics

Tilapia should do better on the more vegetarian diet. Glad you have taken one for the team and tested them on the more carnivorous diet.

It's only 5%+, but the stubbornness of the poo is definitely of a differerent sort.

Update:
The gravel filter under the drain is a winner. The procedure is when the water level is high (because it is becoming clogged) rinse out gravel in a bucket several times, dump the muddy water into the grow bed upstairs, then reassemble the basket like new. Did all that again tonight and it's pretty painless and is catching significant poo.

p.s. The plant sump suddenly cleared up this week from an algae green color.
p.p.s. Twitchy passed away last weekend while we were out of state and the stepson was watching the fish. R.I.P. Twitchy! He's pushing up daisies in the dirt garden now.

Bye bye Twitchy (pssst, which one was he?)

Twitchy was the one of the first batch of goldfish I got last year. I saved him and kept him in the garage, which was a good thing because he had a gimpy mouth and all the rest of the fish in that system died. :shrug:

Apparently I'm not turning over enough, because the fish stopped eating last night and this morning (food just floating on the top). The lower set of beds are not getting as much flow as the upper beds and so they are not flooding and draining as often as the top ones. That and maybe the solids filter is causing a loss of oxygen. Anyway they seemed to be gasping a bit so I hooked up a bubbler which is now making a very nice column of bubbles for them. I hope they will perk up within the hour. I have room for two more beds and I could add another pump to turn things over better, but the flow right now is almost too much for the siphons. I may be redesigning the flow part a bit this Winter.

I am thinking about hooking up the 70 gallon tub as a pigging out/purging tank for the ones I want to eat first. The idea is to have a place to isolate them so I can make sure they get more food than the "gen pop". Then it would be a convenient way to purge them as they would already be isolated. I am going to measure the space under the pier to see if it will fit there. One of the siphons would be routed into that, then the drain for that would overflow into the gen pop tank.

p.s. The solids filter basket is still working great. Some poo had got stuck on a sharp piece of plastic and further poo had tangled up on it, making a thick and long poo rope, swaying in the breeze. I named it "Rupe". How neat!

p.p.s. Maybe I should just put a fork on a motor, ala spaghetti?

Well I bought some more concrete blocks from Lowe's to prop up the pig & purge tank. I also got the drill bit I'll need to drill through the garage wall!

So I'm trying to use my nitrate test, I tested my top-off water first and it is measuring 10ppm nitrates. So, I diluted one tube full of fish water with 9 tubes of top-off water, are these calculations correct?

10 + 10 + 10 ... + 10 + x) / (1000000 + 1000000 + ... + 1000000) = 40 / 100000

(90 + x) / (10,000,000) = 40 / 1,000,000

(90 + x) / 10 = 40
(90 + x) = 400
x = 400 - 90
x = 310 ppm

?

Or should I be looking at 10 / 1,000,000 as 10 of the good stuff and 999,990 of the other stuff and do it that way?

(90 + x) / (999990 * 9 + 1000000 - x) = 40 / 999960
(90 + x) / (9999910 - x) = 40 / 999960
(999960 * (90 + x)) / (9999910 - x) = 40
999960 * (90 + x) = 40 * (9999910 - x)
89996400 + 999960 * x = 399996400 - 40 * x
89996400 - 399996400 = (-999960 - 40) * x
-310000000 = -1000000 * x
310 = x
x = 310ppm

I guess that matches!

its (relativey ) early sunday morning and i'm only on my second coffee after a birthday party last night so forgive me if this sounds stupid, but;

if you added 9:1 that would make the sample water 10% strength of what it actually is. so wouldn't you just multily the measured value by 10?

measured 10ppm x 10 = 100ppm?

oh man, disregard all that! i just read that you're top up water has 10ppm nitrates. too much math for this time in the morning

if you want to check your math, just use some distilled water for your 9 parts test should come out at bang on 100ppm

Yep, I don't have any distilled water here Steve, so I just tried using the 10 parts in 1 million parts literally and tried to figure out the proportions from that.

ok, brains warming up now.

what did the ppm come back with your diluted sample?

The control tap water samples were 10 ppm, the 9 tap + 1 fish water sample was 40 ppm.

(90+x)/10=40

90+x=40x10

x=400-90

x=310

Same as you.

sorry i find it easier re-doing it than reading some one elses math

Update:
Washing poo gravel every other day, seems to be helping with the pee-yellow water. I am suuposed to be taking out and replacing 18 gallons of fish water with tap water about every 2 or 3 days but I have been sick. Haven't measured nitrates but maybe I can do that today. Maybe the RSG filter is helping too. The fish are more energetic at feeding time, but this may be a combination of lowering the solids load, putting the bubbler close to them, and bumping up the temps on the heaters. They seemed to not do badly at 70F/21C but they are happier at the higher temps.

The latest plans are that the outside season is largely over and that I am not going to have a shelter over the grow bed (yet again) before the outside starts freezing. I have planted some things but they are very slow growing compared to warmer weather. The new sprouts have been just coming up for a week now, don't seem to be moving upward fast at all.

I am intrigued by the idea of a "Binge and Purge" tank, where I can isolate the death row inmates from the general population and feed them more intensively, then just stop feeding to purge before taking them out. As a further enhancement on this idea, I am wondering if I can give the binge and purge tank fish pellets and grow the gen pop's food from the water. I.e., the only fish getting processed food would be the end-of-lifers and the gen pop would get duckweed/azolla/? at one level of indirection (to use programmer speak) from the processed food. If it were possible to grow them enough food I think the nutrient levels would be easier to control. It would be on a slower ramp than feeding all of them pellet food.

WTW? (new acronym would - this - work ?) I am thinking about switching over the mortar tub into a duckweed growing tank, either in the basement with four fluorescents or outside with maybe a pane of glass over it to insulate it.

I think you just need to eat some fish to lower your overall fish load, and therefore your overall need to feed. With my half of the fish order, I was way overstocked, and I seem to recall that you were going to be pushing the limits, too. With my system, it seems that 30 large fish is a good limit. I can feed 50g of food a day; that gives me a nitrate under 20 (and sometimes 5), 0 to 0.25 nitrite, and 0 ammonia.

I don't understand why the source of the food would make the nutrient levels easier or harder to control. If you feed the fish, it makes poo.

The idea is to introduce a cascade, the input would be just enough to feed the death row guys (i.e. steak dinners), then the waste from them would be used to produce a lower-nutrient feed for the general population guys (i.e. high filler meatloaf). Right now I'm feeding high nutrient food to all of them which gets one trip through their guts then becomes a problem for the water quality.

Ah, that makes sense, then. You're trying to lower the protein level of what you feed in the system until you can use up the high-protein chow. (This is the "Silver" Zeigler feed, right?) The tilapia seem to love duckweed, but I don't have the space to grow it for them. You could also get yourself a bag of Bronze again, and just feed the main system with that, but "Death Row" with the Silver. Or save the Silver for spring and the goldfish pond. (Everyone has a goldfish pond, right?) I'm going to have to re-stock Bronze in the next couple months. May be a road trip in the future.

One other alternative would be to pour the Silver Zeigler in a cereal bowl with milk and strawberries. I hear it's tasty for breakfast. :yuck: