Backyard Aquaponics
A place to discuss aquaponics

Hi fish people -

I have a new 1600L tank system with 2 goldfish surviving for at least a month. As NH4 was zero, I figured there was no cycling going on, so decided to up the ante.

Picked up 20 silver perch from John at Glenwaters Native Fish on Saturday.
Am running flood and drain 14 times per day, and a big bubbler with 7 airstones night and day.
Have some smallish vegies in 2 x approx 350-400L grow beds, in 20mm scoria.

Night 1:Water temp at the fish farm and at home was 12C. pH at home 6.8.
Day 2: pH 6.8, temp 10.8C, NH4 zero - 1 fish dead
Day 3: pH 7.0, temp 9.5C, NH4 zero - 1 fish dead
Day 4 Didn't measure
Day 5 pH 7.0, temp 9.5C, still no ammonia, 1 fish dead
Day 6 pH 7.2, temp 10.5C, ammonia zero, 4 fish dead

I have only fed twice, on Day 3 and day 6, using finely ground food from the fish farm.
Some of the dead fish have redness around the gills.
Should I be concerned? The gold fish are healthy.

I haven't been adding much seasol to the growbeds, only every 2 weeks or so, added a cap full just before getting the fish.

So the pH is rising, should I add salt?
I don't quite understand the salt bit - is it to lower pH?
How much do you add for that amt water and fish?

Any other suggestions?

Salt is used for two reasons Vegiegirl...

To treat disease... in which case we normally dose to at least 3ppt... that's 3kg of salt per 1000L...

To mitigate against nitrite poisoning... in which case we dose to 1ppt... that's 1kg of salt per 1000L...

I would always recommend salting to 1ppt... whenever you first introduce fish to a tank... if only to "sooth" the fish after transport...

I would advise that you do a nitrite test... and report back... and that you salt to 1ppt regardless...

Also, your water temps are at the lower end of range for Silver Perch... doubtful that they would want to feed more than once or twice a week anyway...

But at those temps, small Silver Perch just may not survive anyway... especially after being transported... and with a drop in temperature...

How big were the Silvers??

Hi just spoke to Karen on the phone i will zip down there tomorrow and have a squize [look] John where she got the fish has his tanks salted to around 5 ppt so i suggested dump in 5 kg asap she has 1600 litres and see how she goes i will also take some water and filter squeezings with me

F&F to the rescue!

Did you make sure she understands what kind of salt to use?

Yep bunnings pool salt same as we all use

You guys are ace

Ok been and seen in short 1 1/2 in silvers and 10 deg water dont mix

Saying that Karen has a nice tidy system with great possibilities first time i have seen ss grow beds
Here's a lesson to be learnt
silvers unless they are over wintered need warm water read the forum and ask a lot of questions if you are not shore

Thanks F&F, really appreciated the visit this am.
Made many notes, so a bit more adjusting to do!
Have purchased a heater, and managed to catch some, so hopefully those will survive.
Others are proving elusive...I figure if they are that fast maybe they are really tough?!
Anyway, I'll try again later.
The toasty warm ones are in a 200 L tank now.
When is it too soon to get non-overwintered ones mailed out? or is it always better to pick up yourself? And if so, is it time when the water is about 18C I'm guessing?

yes when your water temp stays over 18 they will probley survive The thing is with non overwintered ones you will probley have to warm up a bit the next winter
Also if you are going to use trout over winter you will need to seperate the silvers or they will become trout din din
Thanks for the red i am sitting here with a glass now

Thanks F&F - glad you like it!

Got a heater, water got to 17C, no ammonia still, but fish didn't like transfer - maybe were already stressed, so another 3 dead.
Some fast swimming ones couldn't be caught, so there are a couple of survivors - think i'll leave them there, add some goldfish, then get some more sp's for the warmer water.

Just my observations.....

last year in a brand new system, I lost quite a few silvers at temps below 15 degree c.

this year in a mature system I have not lost a single silver over winter, even the tiny juveniles. Some are only a couple of centimeters from tip to tail. Temperatures have got below 10 degree c water temp. Lowest was about 6 degrees for 10 hours or so.

I think the really little ones graze on algae to stay alive, and this is something that only a mature AP tank has.

Thanks for that info, makes sense that a mature system would support them better, as they are obviously surviving in the water they came from at the fish farm!
I have observed them snuffling along the bottom and sides actually - there is some stuff on the sides as I've had it going with a couple of goldies for a while now - not cycling though.
Have decided to get some more sp and keep them heated ready for summer, and also some trout - do goldies, trout and sp mix?
I want to get something going! I figure that the trout will grow a little at least!
What size is feasible to buy trout for a new system?

Any recomendations of transporting 6 400 gram trout 20 minutes away

Blue barrel, battery aerator - only need a small one.