Backyard Aquaponics
A place to discuss aquaponics

I worked out the amount my system could handle as a maximum days feed befor I see ammonia spikes.
I fill up a jar to the marked level, and that's how much they can get in a day. Or less if they don't seem to want it, but never more.

I worked out my filtration capacity by just slowly increasing feed until I started seeing trace ammonia readings. I'd back off a bit, and every two months or so I push it up a little and see what happens. Most often the new limit goes up a little. So I push it a little more, then once I see a trace of ammonia I back off to a limit that I think is safe enough to have a fish die and float around for a day or so before total disaster sets in.

Each adjustment might be 1% of the total I normally feed, so its slow and safe, and wont do any damage if I get it wrong.

I think you just have to feed to your filtration rather than to your fishy appetites.

Thin them out if they want big fat ones, or perhaps, just for this year, look into removing some solids for the last stage before harvest. I put large kitchen sieves under my GB inlets when I had an ammonia spike, and managed to remove an amazing amount of solids in a few days before everything settled out. I think the sieves were taking out around 50%. I just taped them out onto the ground once or twice a day.

It took a couple of days to see the benefit.


and this from the new electronics section... Project: Demand auto feeder with feed limits

Are they calibrated handfuls Arbe?

Lol EB.

They would be pretty uniform amounts.

Chillidude. That is what I was thinking but wanted to make sure I am not doing anything too wrong.

BullwinkleII. Great advise. Glad I posted the question now.

EB: I tested my handfuls tonight: one handful is 42 grams. So they were getting about 120 grams each feed.

As predicted it took 3 days for levels to return to 0 - well almost zero. Nitrite is 0, ammonia is between 0 and 0.25.

Back to feeding tomorrow and more monitoring of levels.

They look like a perfect size to me. Especially when you have 100 in stock. You can't predict the weather but some areas could possibly start getting banks of warmer days and you know what that means. Better to eat 100 x 200g fish than compost 100 x 600g.

Sometimes you just get hungry.....

+1 for thinning out the greedy ones

Not that I would know because I haven't reached that stage yet, but some of my silvers (9 only) are starting to look too tasty for there own good

You tell if they are nearly ready when you start seeing wasabi, soy, and really sharp knives in the growhouse

Fed 120 grams on Thursday morning. Tested water Thursday night: ammonia and nitrite 0.

Tested water Friday morning: ammonia and nitrite both 0. Fed another 120 grams. Tested Friday night: ammonia and nitrite both 0.

Tested this morning. Ammonia 0.5 and nitrite 0.25.

Will hold off on feeding and test again tonight. Fish appear to be hungry as they are coming to the surface when I obtain some vials of water for testing.

Water tests this morning: ammonia a bit higher than 0.25 but not 0.5. Nitrite 0. Water temp: 16 degrees celcius.

120 grams of food consumed in about 10 seconds.

Am currently suffering an ammonia spike. Tested the water last Friday to find that ammonia was about 3 - 4. Nitrite is still ok. Water temp has been a pretty stable 19.

It finally dawned on me today that I should check my pH. It was 6! OMG! I have shell grit on my sump but it doesn't seem to be buffering.

After reading a post on here which said Perth water is ok to use to directly top up your system I did this the other week. I am wondering if this is the cause? Perhaps it isn't ok to use.

All fish are happily swimming around and even greet me when I pop the cover off to test the water as if to say feed me! I already have salt in my system but will add some more to help with the more than likely nitrite spike.

I wouldn't stress to much arbe, at that low a ph your ammo won't be toxic or a while, jut keep an eye on the nitrite (I'm sure you already know this)

Maybe test the water ph? Mine is high, over 7. I reckon your system has cycled causing ph to crash

Just tested the tap water pH. It is 7.2 - 7.6.

I have gone and stired the shell grit up a bit to try and make it release into the water.

I will keep an eye on the nitrite but I tend to agree with you Freoboy: I think my system may have finally cycled.

I reckon just chuck some more hell grit in, and wait a couple of days till you feel them again. Trout won't last much longer anyway, couple of warm days coming up this week. I have a big lump of limestone and shell grit in mine, and ph is still usually lower than 6.5

FWIW shell grit never brought my pH up, whereas baking soda did immediately. I don't know why it never worked for me, was oyster shells, maybe not a large enough amount of it.

How quick was it Dave?