Backyard Aquaponics
A place to discuss aquaponics

hey

wish to get some advice for fish stocking in aquaponics in melbourne. Have tried the murray cod, silver perch, catfish, did not survice in melbourne's winter. Can anyone from melbourne give some idea?

maybe your system is too small?

ive got cod and bass and catfish in with my goldfish, no problem.

they are still tiny too, so they do survive.

are you in the dandenongs or something?

trout do very well over winter, but not summer (unless you are in the dandenongs with a big system)

my friend has many silver perch in his pool system and none ever died from cold.

where did you get your fish? were they posted from up north or did you buy them from glenwaters?

well, i should admit onething that my system is not big, i have a pond with 2500 litre water, connected with a IBC growing bed and two blue barrels growing bed, the growing bed is not big enough, but all the fish are fine and well grow in warmer time, die slowly in winter. and in the same system, my goldfish are all fine. i did talk to my fish supply glenwater, and john thinks the water temp is too low, i measure it before, it is around 10 -11 degree.

i got my fish from glenwater.

the system size sounds fine, right now mine is only a 1400l growbed turned into FT and 6000l biofilter (about 3000l water) with no growbeds at all.

ive had some die off, but there have always been enough survivors (and this is after running zinc water for ages and probably still having low zinc levels)

i dont monitor my water temp, but my friend with the pool did the first year when the perch went in at it got to 10-12c if i remember correctly.

how many did you buy?

if you only bought a few of each, maybe you just need to buy more knowing some will die?

You say its a pond, do you find the dead ones? or could birds be getting them, etc?

when i buy, i buy 50, first time, i have 20 silver perch, 20 bass and 10 catfish, they all die in the first winter, second winter, i have 50 of the murray cod, and they grow fast until winter, start to die off. but in these two years, i have goldfish in the same water, they are fine. so i assume, it is not disease, but temp.

Murray Cod shouldn't be killed by 10-11C water, they just wont eat much. I'ts a lot colder in winter here, and my water was down to 7C, and that didn't kill any.

so they ALL live just fine until temps are very low?

what suburb / side of town / area are you?

They all grow fine until winter, they start to die after mid of winter

Whats killing them do they get white fungus on them or patchy skin

One possibility is rotting uneaten feed in the pond when the water gets that cold they wont eat

When the waters cold the fish just sit there motionless and the waste may not be getting pumped out

I only put lettuce in with my silvers on a string (so I can pull it out) when the waters cold they will chew that back to a stump but wont touch pellets

My systems were getting down too cold (6c some mornings) so I set up heaters

I have black poly laid out controlled by a timer to help heat my water doesn't do a lot but its better than nothing if I'm consistent with my bell management a few sunny days a week will keep mine above 10c morning temp most days its 14 / 16c in the mornings

I take the siphon bells out at night also this saves some heat loss

I have thermometers in my tanks and only put pellets in when the temp is about 18c (afternoon feed)

I also run a few gold fish and yabbies in every tank to clean up uneaten feed

I would advise building a greenhouse over your system (plastic not shade cloth) to build up some heat , perhaps something that can be rolled back once it warms up.

Trout would go well in those temps but they MUST have clean water and wont survive past 25ish degrees so probably give them a miss until you get sorted and have success

Trouble is that plants don't like it that cold as well

I have come to the conclusion that I will need a greenhouse with large roof vents that can be opened to let summer heat out and the ability to roll shadecloth over as required , my systems have produced very little this winter and is simply not worth running pumps for the sake of waiting for the weather to warm up , my previous property was on average quite a bit warmer through the winter so learning curve here for me also

i think it could be some diseases, also i used to have a bad habit to feed too much during winter time, also i heard that the system won't do any good as warm season to get rid of nitrate and nitrite. really think of green house but will see if i have enough space. do you keep the yabbies with your fish in the same tank? will yabbies eat the fish? as i used to keep yabbies in the pond, but one night, i found the yabby is eating a goldfish, not sure if yabby caught the fish, or eat a dead fish. so what fish do you keep in your system? i really wish to keep murray cod, silver perch.

My SP died this year due to cold - 7 degree water temps. My trout in the same tank were/are fine.
No fungal growth on the SP and otherwise they were healthy. Haven't tried MC myself yet however so I have no useful. Info for ya there...

Sounds like trout is the only fish you've not tried - any reason why you don't seem to be considering them?

There's only about 2 months of the year (here) that are too hot for them with my system design but I don't really understand wanting to keep them longer term because they should grow to harvest time before its too hot for them. My system didn't seem overly fussed not having fish Jan/Feb.

sorry to hear you lost some SP too, i was thinking of rainbow, but there is onething that i do not eat rainbow trout normally, also heard someone mentioned about high temp concern.

i really want to keep some fish all year around, so i can harvest it when they reach decent size.

It doesn't appear that you are reading your email so I'm posting my request in your thread -

Hi Aussiecrocodile,

Just a heads up - please try not to quote entire posts any more than necessary, Replying to the post immediately preceding yours, you shouldn't need to paste in the whole quote. Basically just adds bloat to the thread. It's OK if you want to reply to a specific part and are doing it for clarity - just highlight that part and then click the quote button (might take a couple of tries but you can tell if it worked before you finalize your post). Thanks

Scotty435