Backyard Aquaponics
A place to discuss aquaponics

They actually look quite fine apart from the fact that they are dead.

i.e. no discolouration or dryness of the skin,

I did have some millipedes drop into the pond, just wondering if they may have tried to eat these though there is no sign of the other fish eating them. will be doing a water change just in case.

They have slowed down on feeding as well so am wondering if the sudden change in our weather has had an effect. we recently had a strech of 15 days of 35ºC + weather and it has been in the high teens and low twenties since then.

H.

Try to get some duckweed in the tanks, it'll keep the NO3 out of the water and you'll be able to stock for spring.

The temps changes can cause immune system to be low and 18°C is usually a very good temp for freshwater bacteria diseases. In fish farming we now use an additive that is supposed to boost the immune system of the fish before winter and at spring. Mostly vitamins and high quality food, if you have vitamins for humans crush them, mix with honey, fish oil and yeast extract and fish food in a plastic bag. I'd say a tea spoon of honey and fish oil and yeast for a pound of fish. Add oil if the food is not all oily. Mix well so that the additive stick well to the pellets. Let it dry a bit and feed the fish with, it should increase their ability to resist to pathogens.
The things you'll add are full of vitamins, trace elements and many things that are recommended for humans too.
I hope this will help.
Follow the water quality closely as the mix will be polluting more than standard pellets.

Another thing i forgot is to go slowly on water changes, dilute slowly, the swings will be demultiplied with the fish weakness. Syphon slowly and refill the same. Maybe on a few days.

No problems with the sudden drop in water temp here apart from the fish not being as hungry.
Last year I also lost about 3 TT in 24/hours for no apparant reason.

Thanks, I'll see if I can organise it for tomorrow.
The duckweed won't last long with the silvers but it wont hurt. what about some live food like worms etc? I can get my hands on plenty of those.

H.

Hmmmm curioser and curioser...



Thanks amacafish, the water changes will be slow.

H.

Insomnia strikes. Ones wondering, on the dead tan tans, what did their mouths look like. I mean open or closed? Let me know. Also, how much aeration do you have?

Mouths were closed, aeration is not a problem, if you have a look back at some of the photos you will see my autosyphons in action these kick in every 5 minutes or so (never timed). why do you ask?

H.

sometimes if the mouths are open it can mean a DO defficiancy was cause of death. The extremely warm temps could cause a problem with Disslved O2 levels.

It seems species specific himzol.
If temps are ur only variable lately, it would seem a fairly natural solution.
Can't remember if ur carrying high stocking densities etc.

After reading thru the thread I am thinking its the cold water is holding the disolved gases better. As opposed to what I previously said about the low DO. (hadn't noticed temp dropped in thread). Anyway the cool weather would slow the plant growth and possibly cause a spike in ammonia, nitrite, nitrate levels. The tans may be more sensitive.

Also, the water bugs a entering the tanks through the air.

are entering

I'd give a buzz to Bruce from Ausyfish Pty Ltd in Queensland if I were you, he has bred some in captivity and is one of the best fish information resource in Australia. I've worked there and he is brilliant.

Stock density is low, in that part of the system it (was) 15 or so cats (100mm) and about 12 Silvers (200mm), this is the kidney pond sump section of my system. There are approx 30 small (30-50mm) goldies in the "green bucket" atached to this system as well. Plant growth has been good and the system seemed reasonably well balanced. tested water every week, everything was stable..




I'll see if I can get in touch with Bruce later today, I got the tan tans from him so he may be able to shed some light on this predicament.

thanks folks.

H.

Please let us know what he has to say about it Himzol